Pests of Specific Crops

Pests of Specific Crops 14 

(updated August 2013) 

Pesticide products are listed in alphabetical order and not by effectiveness. This is not a complete list of all product 

formulations that may be registered for use on a particular crop. Product registrations and labels may change. Read the 

LABEL CAREFULLY before applying any pest control product. is used to indicate products that are classed as danger 

poison. 

For commercial tree fruit see also the Ministry’s Tree Fruit Production Guide. For landscape plants see also the Home & 

Garden Pest Management Guide for British Columbia. 

Pest Description 

ABIES – FIR 

Diseases: 

Current Season Needle Necrosis: This 

physiological disorder affects grand and 

noble firs. Symptoms appear in late June to 

early July on new growth and can differ 

greatly from one tree to the other. Portions of 

the needles turn yellow, then tan, and finally 

darken to a reddish brown. In some cases, 

entire needles change colour followed by 

severe needle loss. 

Grovesiella Canker (Grovesiella abieticola): Flagging 

and dieback of lower branches to yellowing, 

stunting and death of trees. Needles yellow 

and drop. Cankers often appear at the base of 

the trunk. The infected branch or trunk swells 

above the canker, which appears as an 

elongated depression. Shasta and white pine 

are more susceptible than grand or noble fir. 

Interior Needle Blight (mainly associated with 

Mycosphaerella spp.): Noble and grand fir. 

Random browning of older needles on lower 

branches in late summer/fall. Needles remain 

attached to the branch and do not shed as 

with physiological stress. Black fungal 

fruiting bodies appear on underside of 

needles in spring. 

Needle Casts; Foliar and Twig Blights (Lirula spp., 

Lophodermium spp. and Rhizosphaera spp.): 

Needles turn brown or yellow and drop, and 

twigs dieback. Black fungal fruiting bodies 

can be found on dying needles and twigs. 

Phaeocrytopus nudus is a common secondary 

saprophyte on dead twigs and needles. 

Chemical Control 

(rate per 100 L water; or per 

unit area if indicated) 

Foliar application of calcium 

chloride during shoot elongation in 

spring can reduce incidence, but is 

often phytotoxic, so not generally 

recommended. 

BANNER MAXX: 35 mL (for use 

on Christmas trees only) 

COPPER SPRAY 50: 400 g 

FLINT 50WG: 210g/ha 

Apply when new growth starts in 

spring and repeat during 

prolonged rainy periods. 

Lophodermium Needlecast: 

Daconil 2787F: 2.4-4.8 L/ha 

Bravo Ultrex 90 SDG: 1.3-2.7 kg/ha 

Daconil Ultrex: 1.45-2.9 kg/ha 

Cultural 

Management 

The cause and control of this 

disorder is unknown. It 

occurs in open fields, but not 

in partially shaded 

situations. 

Trees with canker infections 

should be removed and 

burned. Do not put new 

plantings close to older 

diseased trees. 

Improve air circulation by 

weed control and pruning of 

lower branches. 

Needle cast and blight fungi 

on fir are usually weak 

pathogens or secondary 

invaders following 

environmental damage. 

Nursery Production Guide Pests of Specific Crops • 1


Phytophthora Root Rot and Shoot Blight 

(Phytophthora spp.): Death of seedlings; 

browning and flagging of lower branches on 

older trees; stunting and sunken cankers on 

stems or on trunk just above soil line. There is 

swelling above the canker and wood is stained 

brown under the bark, unlike Grovesiella. Trees 

are usually affected within 3-4 years of 

planting and often in pockets or groups. 

Rusts: 

Fir-Fern Rust (Urediniopsis spp.) 

Fir-Bracken Rust (Urediniopsis spp.) 

Fir-Fireweed Rust (Pucciniastrum spp.) 

Fir-Blueberry Rust (Pucciniastrum spp.) 

Fir-Willow Rust (Melampsora sp.) 

Fir-Broom Rust (Melampsorella spp.) 

White or yellow, cylindrical fungal structures 

called “aecia” appear on the underside of 

needles. Alternate hosts (fern, fireweed- 

Epilobium spp. and willow) have yellow leaf 

spots. Severe infestations can cause needle 

drop, growth loss or death of trees. 

Scleroderris Canker (Gremmeniella abietina): Does 

not occur in BC. Causes shoot blight and 

cankers on pines and balsam fir in Eastern 

Canada. 




See General Disease Management: 

Root Rots Caused by Phytophthora 

and Pythium, Chapter 9. 

Cultural 

Management 

Do not plant Abies spp. on 

poorly drained soils. 

Remove alternate hosts 

within 300 m of fir. Cool, 

moist spring weather 

promotes infections. 

Seedling Blight (Sirococcus conigenus): See under PICEA - SPRUCE and General Disease Management: Sirococcus Blight, 

Chapter 9. 

Insects: 

Balsam Gall Midge (Paradiplosis tumifex): The adult 

midge appears when fir buds are developing. 

The female lays eggs in the opening buds. The 

larva feeds at the base of a needle, initiating the 

growth of gall tissue that will eventually enclose 

the larva. Galls are formed on current season 

needles. Infested needles yellow and abscise in 

the fall. The larvae overwinter in the soil. 

Balsam Woolly Adelgid (Adelges piceae): Branches 

and tips become swollen, which results in a 

“bird-claw” appearance. White woolly masses 

appear on bark. Most severe damage on Fraser 

and alpine fir. 

ACER - MAPLE 

Diseases: 

Anthracnose (Kabatiella apocrypta and Discula spp. 

(Apiognomonia)): Brown to white irregular 

blotches appear on the leaves. Twigs dieback. 

The causal fungus overwinters on twig cankers 

from which spores are splashed when hit by 

rain or irrigation water. 

MOVENTO 240 SC: 585 mL/ha 

BANNER MAXX: 28 mL 

Apply every 14 days. Do not 

apply more than 4 times per year. 

All Abies must be grown 

under permit. See British 

Columbia Plant Protection 

Regulations, Chapter 2. 

Remove dead and damaged 

twigs and those with visible 

cankers to reduce inoculum. 

Minimize sprinkler irrigation 

or schedule applications so 

the foliage has opportunity 

to dry off quickly. Rake and 

burn fallen leaves. 

2 • Pests of Specific Crops Nursery Production Guide


Bacterial Blight (Pseudomonas syringae pv. syringae): 

Infection occurs in cool, wet weather in spring 

and fall. Recent research in Oregon suggests 

that most infections on maple occur in the fall. 

Cinnamon Canker or Coral Spot Canker (Nectria 

cinnabarina): Orange-red or pink-coral coloured 

fungal “cushions” appear on dead or dying 

branches. This is a weak pathogen or saprophyte 

which usually affects branches killed or 

damaged by other factors, such as winter injury. 

Leaf Scorch (drought and Xyella fastidiosa bacterium): 

Browning and withering of leaves affecting the 

margins first and the veins last is common on 

red and lace leaf varieties of A. palmatum. It is 

usually caused by heat and drought. A 

bacterium called Xyella can also contribute to 

leaf scorch on landscape trees. Xyella has been 

found on Vancouver Island. 

Nectria Canker (Nectria galligena): Causes blistered 

bark and sunken, girdling cankers on twigs, 

limbs and trunks. Leaves and branches dieback 

above the cankered area. Edges of cankers 

become rolled and swollen in the second year 

after infection. Infection is through pruning or 

cutting wounds or new buds. Bright red fungal 

structures (perithecia) may be seen in fall at the 

edge of cankers. 

Tar Spot (Rhytisma acerinum): Causes circular black 

spots on the leaves in late summer of Norway, 

red, silver and sugar maples. The pathogen 

overwinters on fallen leaves. Spores spread from 

the soil to young leaves by wind or rain splash. 





Bacterial Blight, Chapter 9. 

There is no chemical control for 

the bacterial disease. 


COMPASS 50WG: 14-21 g 

Wilt (Verticillium dahliae): See General Disease Management: Verticillium Wilt, Chapter 9. 

Insects and Mites: 

Boxelder Bug (Leptocoris rubrolineatus): The adult bug 

is 1.2 cm long, black with red stripes on the 

mid-section of the body and red veins on 

wings. Nymphs are bright red. Associated with 

key-bearing boxelder trees. Occasionally 

hibernate in houses. 

Forest Tent Caterpillar (Malacosoma disstria): 

Caterpillars feed on leaves in summer. In the 

Interior, they occur in the spring and do not 

make tents. 

SEVIN T&O: 230-350 mL 

Spray when insects are first seen. 

See General Insect and Mite 

Management: Tent Caterpillars and 

Skeletonizers, Chapter 11. 

Maple Bladder Gall Mite (Vasates quadripedes): It feeds ACECAP 97: Apply only if very 

on the undersides of maple leaves in the spring high populations of galls develop 

causing numerous galls or a red, fuzzy growth on foliage. For rate, see label or 

on the leaf tissue. The `gall’ eventually surrounds General Insect and Mite 

the mite. The mite exits the gall before leaf fall Management: Aphids, Chapter 11. 

and overwinters at the base of the buds. There 

are several generations per year. 

Cultural 

Management 

All maples except sugar 

maple (A. saccharum) are 

susceptible. A. palmatum 

‘Sanga Kaku’ and ‘Oshi Beni’ 

are highly susceptible. 

Prune out affected branches 

and twigs. Protect young 

trees from winter injury. 

Avoid planting susceptible 

varieties in areas where they 

will be exposed to hot, dry 

winds. Plants in containers 

or in well-drained soil must 

be kept well-watered during 

hot weather. 

Prune out dead and diseased 

twigs promptly, disinfect 

pruners between trees. Prune 

only during dry weather. Do 

not leave long stubs when 

removing the rootstock top 

growth after the scion has 

started to grow. 

Collect and dispose of fallen 

leaves and prune trees to 

improve air circulation in the 

crown. 

Do not plant maples in soil 

where potatoes, berries or 

Verticillium-infected trees 

have been grown. 

Remove overwintering egg 

masses encircling twigs. 

During the growing season, 

prune off branches with tents. 

These mites do not damage 

landscape trees but can be 

unsightly on nursery stock. 



AESCULUS - HORSE CHESTNUT 

Diseases: 

Leaf Blotch (Guignardia aesculi): Reddish-brown leaf 

spots and blotches with bright yellow margins 

appear in summer. Very similar to scorch (see 

below) but with small black fungal fruiting 

bodies (pycnidia) in the centre of the spot. 

Pycnidia develop early in June and release 

spores that initiate secondary infection cycles 

throughout the summer in wet weather. 

Leaf Scorch (environmental): Large, reddish-brown 

blotches with bright yellow haloes appear 

during hot weather in summer, often on 

margins of leaves. No black fungal fruiting 

bodies are present, unlike Guignardia blotch (see 

above). 

AMELANCHIER - SASKATOON 

Diseases: 

Black Leaf and Witches’ Broom (Apiosporina collinsii): 

Typical “Witches’ broom” symptoms are on 

new growth. Suckers are infected. Infected 

leaves roll downward and become covered 

with a black mould on the upper surface and a 

grey felt-like mat on the lower surface. It has 

been found occasionally on fruit in the Interior. 

Leaf and Berry Spot (Entomosporium mespili): Small, 

angular leaf spots on foliage and fruit. Worse 

under high moisture and warm temperatures. 

Petioles, stems and flower stalks may also be 

infected causing leaf and fruit drop. 

Monilinia Brown Rot and Mummyberry (Monilinia 

amelacchieris): Brown spots on leaves and fruit, 

mummified fruit. Favoured by humid weather 

and insect damage. Can also cause blossom 

blight and twig infections. 




Nursery or newly-transplanted 

trees: 

DACONIL 2787F: 250 mL 

DACONIL Ultrex: 150 g 

Apply at bud break and repeat 

every 7-14 days as needed. 

FUNGINEX DC: 300 mL. Apply 

once between bud break and 

white tip stage; 60 days to 

harvest. 

KUMULUS DF: 7.5 kg/ha. Apply 

at flower bud break and 10-14 

day intervals. 

TOPAS 250E: 500 mL/ha; apply 3 

times a year at white tip, petal 

drop and green fruit stage. 

No fungicides are specifically 

registered for this disease, but 

application of TOPAS 250E for 

leaf and berry spot (above) 

should help to control Monilina 

rot also. 

Cultural 

Management 

Rake and destroy fallen 

leaves where the fungus 

overwinters. Established 

landscape trees may be 

infected every year without 

serious injury or decline. 

Fungicide applications are 

not usually necessary or 

practical on large, landscape 

trees. 

May appear on susceptible 

trees every year, but is rarely 

damaging in the long term. 

Good growing conditions 

and proper watering may 

reduce the severity of 

symptoms. 

Remove and destroy all 

infected seedlings and 

transplants. Prune shoots 10- 

20 cm below the infected 

area on mature plants, 

usually after leaf drop in the 

fall. Remove and burn all 

infected leaves and 

prunings, and any plants 

with crown infections. 

Increase air circulation and 

reduce leaf wetness by 

spacing nursery plants, 

controlling weeds, and 

avoiding overhead 

irrigation. Remove and burn, 

bury or compost fallen 

leaves if severe disease; or 

disc under in larger 

orchards. Prune out lower 

branches in orchards. 

Remove and burn, bury or 

compost mummified berries 

and fallen leaves. 

Powdery Mildew (Microsphaera podosphaera or Erysiphe spp.): See General Disease Management: Powdery Mildew, Chapter 9. 



Rusts: Fungal fruiting bodies called “aecia” occur in 

yellow-brown leaf spots. Leaf drop, swelling of 

infected petioles, and mummification of fruit are 

common symptoms. The alternate host (juniper) 

is required for infection to recur each year. 

Common rusts (Gymnosporangium spp.) that 

produce “aecia” on Amelanchier in W. Canada: 





Rusts, Chapter 9. 

Clavariform Rust (Gymnosporangium clavariiforme): Yellow-brown leaf spot; fruit 

mummification. Common in Coastal BC. Aecia also occur on Crataegus (hawthorn) 

and other Rosaceae. Alternate hosts are in Juniperus Sect. Oxycedrus. 

Inconspicuous Juniper Rust (G. inconspicuum): Swelling of petioles; 

mummification of fruit. Occasional in Southern Interior only. Aecial hosts are 

Amelanchier and hawthorn. Alternate hosts are Juniperus Sect. Sabina. 

Juniper Broom Rust (G. nidus-avis): Common in Southern Interior. Other aecial 

hosts are quince and mountain ash. Alternate hosts are in Juniperus Sect. Sabina. 

Nelson’s Juniper Rust (G. nelsonii): Yellow leaf spot. Common in Southern Interior. 

Aecia on Amelanchier only. Alternate hosts are in Juniperus Sect. Sabina. 

Quince Rust (G. clavipes): Swelling of petioles; mummification of fruit. Not 

common in BC. Aecia also occur on many other Rosaceae species including quince, 

pear, apple, cotoneaster and hawthorn. Alternate hosts are in Juniperus. 

ANDROMEDA POLIFOLIA - BOG ROSEMARY 

Diseases: 

Red Leaf Spot (Exobasidium vaccinii): Red circular 

spots appear on upper side of leaves followed 

by defoliation. Symptoms usually appear in the 

early spring, although infection probably 

occurred during the previous fall/winter rains. 

ARCTOSTAPHYLOS - KINNIKINNICK 

Diseases: 

Root Rot (Pythium/Phytophthora spp.): Soft, brown 

roots on container plants. Basal rot of cuttings 

and poor rooting. 

AZALEA and RHODODENDRON 

Diseases: 

Cylindrocladium Blight and Root Rot 

(Cylindrocladium scoparium): The pathogen 

attacks a broad range of ornamentals, causing 

leaf spots, stem cankers, root rot and wilt. It is 

spread in soil and water, and by wind. Disease 

is favoured by high humidity and high 

temperature. It overwinters as microsclerotia in 

soil and infected plant tissue. 

Damping Off/Basal Rot of Cuttings 

(Pythium/Phytophthora spp. and other fungi): 

See also Root Rot, Wilt and Foliar Blight, below. 

Leaf Burn (Environmental): Leaves become brown 

then grey to white. Margins and interveinal 

areas are normally affected first. Leaf burn may 

be due to summer sunburn, winter desiccation 

or salt injury. 

Cultural 

Management 

Remove the juniper hosts 

listed below from within 2 

km of Amelanchier plantings. 

Remove Juniperus communis. 

Remove J. scopulorum. 

Remove J. horizontalis and 

J. scopulorum. 

Remove J. horizontalis and 

J. scopulorum. 

Remove all junipers from 

within 2 km of Amelanchier 

plantings. 

Overwinter container stock in 

polyhouses to help prevent 

disease spread; avoid overhead 

watering and reduce humidity 

in greenhouses. 

See General Disease Management: Damping Off and Stem Rot of 

Cuttings and Root Rots Caused by Phytophthora and Pythium, 

Chapter 9. 

PHYTON 27: 125-275 mL 


Cuttings, Chapter 9. 

Grow sun-sensitive varieties 

in partial shade, and wintersensitive 

varieties in 

sheltered locations. Avoid 

salt injury from overfeeding. 



Leaf Gall (Exobasidium vaccinii): This fungus 

overwinters on azalea bark and bud scales, 

infecting opening buds in spring. Leaves 

become fleshy, thickened, and covered in a 

white bloom of spores. 

Leaf Spots (Phyllosticta, Colletotrichum spp. and other 

fungi): These fungi are usually weak pathogens 

that infect winter or sun-damaged leaves. Spots 

and blotches are dark brown, zonate and may 

cover half the leaf area. Black fungal fruiting 

bodies are often present in the spots in humid 

weather. 

Lime-induced Chlorosis (Iron Deficiency): Leaves 

yellow between the veins, from margins 

inward. Veins remain green. 

Powdery Mildew (Microsphaera spp.): Large brown 

areas or faint yellow spots may appear on 

leaves in early spring. White powdery fungal 

growth may be on the underside of these areas. 

Root Rot, Wilt and Foliar Blight (Phytophthora spp.): 

Plants wilt and leaves curl and droop. Roots are 

brown and soft, sometimes only on one side of 

the plant. The rot may extend into the crown, 

where the advancing discolouration shows a 

distinct line with healthy tissue. Leaf and stem 

blight may occur without root rot. Symptoms 

are blackening of leaves, stems and petioles. 

Rust (Chrysomyxa spp.): Rust first appears as yellow 

spots on the upper leaf surface and brown to 

purple spots on the lower surface. Blisters form 

on the lower surface, which rupture to expose 

orange-red pustules. Several generations can 

occur in one growing season. It will overwinter 

on rhododendron and azalea and cause new 

infections each spring. Spruce may be an 

alternate host for some of these rust species. 

Tissue Proliferation (Genetic or Physiological 

Disorder): A large gall occurs at the base of 

rhododendron stems that resembles crown gall 

infection. Small shoots often develop from the 

gall. Galls may also be present on stems. 

Growth is not usually affected, but large galls 

may cause gradual decline of the plant and 

stems may break off at gall sites. 

Insects: 

Lace Bugs (Stephanitis pyrioides): Small white spots 

appear in a dense mass on leaves in early 

spring. Damage resembles mite injury. Tiny 

lace bug nymphs can be seen on the underside 

of damaged leaves. 




Commercial nurseries: 

Application of DACONIL 2787 

for foliar Phytophthora blight (see 

below) should provide some 

control of these diseases also. 

(See Root Rot, Wilt and Foliar 

Blight, below.) 

Apply an iron chelate foliar 

fertilizer spray or soil 

application. 

Cultural 

Management 

Do not overhead irrigate 

where leaf gall has been a 

problem. Remove and destroy 

leaves with galls as they 

appear. Reduce greenhouse 

humidity. 

Collect and compost, bury or 

burn affected leaves and 

fallen leaves. Provide good 

plant care and proper 

nutrition. Plant sun-sensitive 

varieties in shaded areas and 

protect frost-sensitive 

varieties from winter injury. 

If soil is high in lime, 

incorporate organic matter or 

a sulphur-containing 

fertilizer. Work soil shallowly 

to avoid damaging feeder 

roots close to surface. 

See General Disease Management: Powdery Mildew, Chapter 9. 

Foliar blight: 



May discolour blooms. 

Soil drench: 

TRUBAN 30WP: 0.6-0.9 kg/100 m 2 

TRUBAN 25EC: 115-240 mL/40 m 2 

SULPHUR (DOMESTIC): 0.4 - 0.9 

% or other formulations. See label 

for rates and application. 

Use disease-free stock. Place 

containers on coarse, welldrained 

beds. Avoid heavy, 

wet soils for field growing. 

See Appendix H for a list of 

Rhododendron species and 

varieties that are resistant to 

root rot. 

Plants growing in crowded, 

damp or shady locations are 

more likely to become 

infected. Collect and destroy 

infected leaves. See General 

Disease Management: Rusts, 

Chapter 9. 

Provide good growing 

conditions. Rogue out 

affected plants if desired. 

See General Insect and Mite Management: Lace Bugs, Chapter 11. 



Mealybugs: These scale-like insects have a soft scale 

that is covered in white, powdery wax. They 

feed on the sap of plants and produce 

honeydew. The honeydew attracts ants and 

often leads to the growth of sooty mold. 

Affected plants appear unthrifty and yellow. 

Root Weevils: Larvae girdle roots and crown tissue, 

and the adults notch leaf margins. 

BERBERIS – BARBERRY 

Diseases: 



Leaf Spot/Anthracnose (Phyllosticta spp./Gloeosporium berberidis): See Mahonia. 

BETULA – BIRCH 

Diseases: 

Leaf Blister (Taphrina spp.): This fungal disease 

related to peach leaf curl causes red blisters and 

curling of leaves. 

Insects: 

Apple & Thorn Skeletonizer and Other Caterpillars: 

Caterpillars are about 12 mm long, yellowish to 

greenish with many black dots. They begin 

feeding on underside of leaves, later moving to 

upper surfaces. Silken webs are formed, curling 

the leaves. The feeding “skeletonizes” leaves. 

Birch Leafminer (Fenusa pusilla): The adult is a black 

sawfly (3 mm long) that lays eggs in young 

leaves. The white larvae mine the leaves, which 

turn brown. There are 2 generations per season. 

Bronze Birch Borer (Agrilus anxius): Usually attacks 

weak or injured trees. The adult is a 13 mm 

long, olive-bronze beetle. Adults appear in 

May-June and lay eggs in bark crevices. Larvae 

(grubs) up to 15 mm long, chew tunnels under 

the bark, girdling twigs and branches and 

causing the upper part of the tree or branch to 

dieback. Chlorotic leaves and sparse upper 

branches are the first symptoms. Lumpy bark 

and half-moon-shaped beetle exit holes can be 

found. 

BUXUS – BOXWOOD 

Diseases: 

Boxwood Blight (Cylindrocladium buxicola): It was first 

detected in North America in 2011. The 

pathogen is spread by wind-driven rain and 

splashing water. Symptoms include brown leaf 

spots, black streaks on stems, and rapid 

defoliation. Clusters of spores are produced by 

the white fungal growth (mycelium) on the 

underside of leaves under warm and humid 

conditions. It does not infect roots. It 

overwinters in the plant and leaf debris. 

Cultural 

Management 


See General Insect and Mite Management: Mealybugs, Chapter 11. 

See General Insect and Mite Management: Root Weevils, Chapter 11. 

Prune out infected leaves and 

twigs if practical and rake 

fallen leaves. 

See General Insect and Mite Management: Tent Caterpillars and 


See General Insect and Mite Management: Leafminer/Needle Miners, 

Chapter 11. 

DURSBAN WSP: 44.8 g 

PRO DURSBAN TURF: 50 mL 

If insecticide treatment is 

necessary, make three 

applications at 2-3 week 

intervals during June and July 

to control adults before they lay 

eggs. Thorough coverage is 

important. Insecticides will not 

kill grubs under the bark. 

DACONIL 2787: 250 mL 

SWITCH 62.5: 100 g 

NOTE: These are emergency 

registrations that expire on 

December 31, 2013. 

Drought-stressed trees are 

more susceptible. Keep trees 

healthy to prevent borer 

invasion (e.g. provide with 

optimum fertilizer and water). 

Prune, burn or chip 

wilted/dead branches to 

destroy larvae in the wood. 

Appendix A ranks 

susceptibility of white-barked 

birch to birch borer. 

Inspect incoming plants for 

symptoms and isolate from 

existing boxwood stock for at 

least 3 weeks. Sanitize pruning 

tools and collect leaf debris. Do 

not plant new boxwoods into 

landscapes with mature 

boxwoods. 



Volutella Leaf and Stem Blight (Pseudonectria 

rousseliana): Causes branch dieback and leaves 

on affected branches to yellow and then turn 

straw-tan in color. Diagnostic pink fungal 

spore-producing structures develop on the 

underside of affected leaves. 

Insects: 

Boxwood Leafminer (Monarthropalpus buxi): 

Leafminers overwinter in the larval stage in the 

leaves. In April they pupate in an orangecoloured 

casing and emerge as a gnat-like fly 

when Weigela begins to bloom. Eggs are laid in 

the current year’s foliage. Damage is from the 

larvae that hatch and feed within the leaves. 

Boxwood Psyllid (Psylla buxi): Eggs, orange in colour, 

overwinter between bud scales. Nymphs 

emerge when the buds open. Terminal leaves 

become cupped and protect the feeding insects. 

Adults, greenish jumping “plant lice”, appear 

in late spring. 

CALLUNA - HEATHER 

Diseases: 

Root Rot (Phytophthora spp.): Infection first occurs in 

fibrous roots, then spreads to the entire root 

system and crown. Individual branches 

dieback or yellow, followed by plant death. 

CAMELLIA 

Diseases: 

Botrytis Grey Mould (Botrytis cinerea): Flowers, buds, 

leaves and petioles brown and drop under high 

humidity. Dead plant parts are covered with a 

grey to brown, fuzzy mould. 

Bud Drop/Brown Petals (Environmental): Flower 

bud drop may occur if plants are located in 

sites exposed to cold, dry winds or summer 

heat. Bud drop can also be caused by low 

winter temperatures, over-watering or drought 

stress. Many older varieties are not winter 

hardy in BC and regularly drop flower buds. 

Bud drop will also occur if more buds develop 

than the plant can support. Brown petals result 

from spring frost damage to flower buds. 

Flower and Petal Blight (Ciborinia camellias 

(Sclerotinia camelleae)): Only flowers are 

infected. Small brown spots on petals later 

enlarge until the whole flower browns. Hard, 

brown to black fungal bodies (sclerotia) 

develop on the base of old infected flowers. 

These can survive in soil for several years. 




Apply an insecticide as soon as 

growth starts in the spring. See 

General Insect and Mite 

Management: Leafminer / Needle 

Miners, Chapter 11. 

SEVIN T&O: 230-350 mL; spray 

when new growth begins, or 

when the insect or damage is 

first seen. 

Cultural Management 

Prune and dispose of dead 

branches and leaves in the 

crown. Maintain good air 

circulation to promote rapid 

drying of foliage. 

Gather and dispose of fallen 

leaves to reduce the number of 

leafminers. 

For bed and container-grown plants, see General Disease 

Management: Root Rot Caused by Phytophthora and Pythium, Chapter 

9. 

For cutting propagation, see Damping Off and Basal Rot of Cuttings, 

Chapter 9. 

See General Disease Management: Botrytis Blight and Storage Moulds, 

Chapter 9. 

CAPTAN 50-WP: 200 g 

CAPTAN 80-WP: 125 g 

MAESTRO 80DF: 125 g 

Plant in sheltered areas in welldrained 

soils that have good 

organic matter content. To 

avoid frost damage, choose 

sites that do not receive early 

morning sun. Select hardy 

varieties. Water during hot, dry 

weather. 

Remove and destroy infected 

flowers. Rake and burn old 

leaves and infected flowers. Do 

not compost. Remove surface 

soil beneath heavily infected 

plants. 



Insects: 

Mealybugs: These scale-like insects are covered in 

white, powdery wax. They feed on plant sap 

and produce honeydew, which attracts ants 

and leads to the growth of sooty mold. 

Affected plants appear unthrifty and yellow. 

Root Weevils: Both black vine and strawberry root 

weevils attack camellia. The adults feed on 

leaves; larvae on roots and the base of stems. 

CANNA LILY 

Diseases: 

Canna Yellow Mottle Virus (Badnavirus): It was 

detected in the Province in 2007. The 

symptoms include yellowing and mottling of 

leaf veins. It is reported to only infect Canna 

lilies. It is spread by propagating from infected 

stock plants. Insects have not been shown to 

transmit this virus. Canna Mosaic Virus is also 

known to infect cannas in North America. 





See General Insect and Mite Management: Mealybugs, Chapter 11. 

See General Insect and Mite Management: Root Weevils, Chapter 11. 

Remove and destroy infected 

plants. It is important to use 

virus free stock for production. 

CEDRUS - ATLAS CEDAR, DEODARCEDAR, CEDAR of LEBANON 

Diseases: 

Tipblight (environmental Injury plus Sirococcus and 

Sclerophoma spp. fungi): Twig tips dieback in 

early spring, often forming a “hook”. Damage 

can be extensive in years with warm winters 

and occasional frosts, and very wet springs. 

Both fungi have been found associated with the 

disease in the Pacific Northwest. 

CEANOTHUS 

Diseases: 


Apply when new growth starts 

in the spring and repeat 3-4 

times at 10 day intervals. 

Prune out infected twigs. 

Protect small trees from frost 

damage, if possible. The 

disease is much less severe in 

warm, dry springs. 

Basal Rot of Stem Cuttings (Pythium/Phytophthora spp. and other fungi): See General Disease Management: Damping Off 

and Stem Rot of Cuttings, Chapter 9. 

CHAMAECYPARIS - FALSE CYPRESS, YELLOW CEDAR, PORT-ORFORD 

CEDAR, LAWSON’S CYPRESS 

Diseases: 

Cypress Root Rot (Phytophthora lateralis primarily; 

also Phytophthora cinnamomi and other spp.): 

Roots of Lawson’s cypress become infected by 

Phytophthora during periods of high soil 

moisture or flooding. Infection moves into 

larger roots and finally into the base of the tree, 

causing a dark discolouration of the sapwood. 

Foliage begins to lose colour, turning 

completely brown within a few months. Large, 

healthy trees often die completely in one 

growing season once infection sets in. 

There is no effective fungicide 

treatment. 

Use Lawson’s cypress that is 

grafted onto a resistant 

rootstock. Chamaecyparis 

nootkatensis, C. pisifera and C. 

thyoides are resistant, but the 

graft union may not be longlived. 

In the landscape, do not plant 

Lawson’s cypress in areas 

subject to flooding. Replace 

dead trees with resistant 

species, such as Thuja plicata. 



Foliar Blights (Kabatina thujae, Seiridium cardinale and 

Seiridium unicorne): Foliage on individual 

branches turns yellow, then brown to grey 

before shattering, eventually leaving large bare 

areas. Twig canker/dieback often occurs on 

new growth. These fungi also cause foliar 

blights on Thuja. 

Insects: 

Cypress Tip Moth (Argyresthia cupressella): See 

description under JUNIPERUS - JUNIPER. 

Juniper Scale (Carulaspis juniperi): This scale attacks 

cones, twigs and needles, causing bushes to 

turn greyish or yellow. Little new growth is 

produced and individual branches can die. 

Little honeydew is generated. The adult scale is 

grey and round. Crawlers appear in June. 

CLEMATIS 

Diseases: 

Botrytis Blight (Botrytis cinerea): Is a common cause 

of leaf blight on cuttings and greenhousegrown 

plants. It causes large, necrotic leaf 

lesions and dieback of petioles, often in 

conjunction with Ascochyta. A grey, fuzzy 

mould appears on dead tissue in humid 

conditions. 

Powdery Mildew (Erysiphe polygoni): Leaf and flower 

surfaces become covered with white powdery 

patches. Often occurs or is more severe on 

plants grown in shade. 

Stem Rot and Leaf Spot (“Clematis Wilt”) (Ascochyta 

clematidina): Attacks the roots, crown and stem 

near the soil line. Individual shoots wilt 

suddenly when stems are infected and girdled 

at the base. Wounds and warm, wet conditions 

favour infection. On leaves, small water-soaked 

spots with reddish margins enlarge to form 

brown circular/oval lesions. Black fungal 

fruiting bodies called “pycnidia” can 

sometimes be seen on infected tissue. 





If disease occurs every year, 

spray once prior to fall rains 

and every 14 days in spring to 

protect new growth. 


Avoid crowding and overhead 

watering. Avoid drought 

stress. Prune out affected 

branches below cankers. 

Sanitize pruning tools between 

cuts with 10% bleach, Lysol or 

other disinfectant. 

If damage is slight, infected 

foliage can be pruned out in 

mid-summer. See under 

JUNIPERUS – JUNIPER. 

See General Insect and Mite Management: Scales, Chapter 11. 

SENATOR 70WP: 65-85 g 

ROVRAL 50WP-WDG: 100 g 

Crop injury may occur. Test on a 

small area first before treating 

entire crop. 

See General Disease 

Management: Botrytis Blight 

and Storage Moulds, Chapter 9 

and Stem Rot and Leaf Spot 

(below). 



Use disease-free stock plants 

and maintain strict sanitation 

at propagation. Remove and 

destroy diseased plants. 

Reduce greenhouse humidity 

and overhead watering as 

much as possible. The disease 

is usually not a problem in the 

landscape, since the humidity 

is often too low for infection 

to occur. 

In Europe, there are reports of 

a similar disease (“clematis 

wilt”) being caused by a 

Coniothyrium fungus. This 

disease is not present in North 

America. 



CORNUS - DOGWOOD 

Diseases: 

Anthracnose (Discula destructiva): Large wedgeshaped 

blotches appear on leaves in spring. 

Severe defoliation and twig cankers may result. 

If repeated for several years, the trees may 

weaken and eventually die. Cornus ‘Eddie’s 

White Wonder’, C. florida (Eastern Dogwood) 

and C. kousa (Japanese Dogwood) are more 

resistant than C. nuttallii (Western Dogwood). 

Crown Canker (Phytophthora cactorum): This soilborne 

organism infects the base of the trunk 

(crown) at the soil line, either through the roots 

or through injury to the bark. Infected trees lack 

vigour and slowly dieback. Wood beneath the 

bark of cankers is discoloured. The tree dies 

when the canker finally girdles the trunk. 

Phyllosticta Leaf Spot (Phyllosticta): The symptoms 

include circular to angular leaf spots with 

purple borders that develop in late summer 

and fall. 




Nursery crops: 

BANNER MAXX: 28 g 

Apply every 14 days; no more 

than 4 applications per year. 

NOVA 40W: 34 g 

NOVA and BANNER have the 

same mode of action. To prevent 

disease resistance, do not 

alternate these products. 

Landscape: 

Dormant sprays with lime 

sulphur, or application of 

fungicides as recommended for 

Septoria Leaf Spot (see below) 

may be helpful. 

There are no effective chemical controls. 


Do not grow or sell highly 

susceptible varieties. On small 

plants isolated from large 

infected trees, picking off the 

first diseased leaves in spring 

may be beneficial. Raking and 

burning fallen leaves may 

significantly reduce 

overwintering inoculum. If 

severe disease continues, 

remove and replace with 

more resistant varieties. 

Management: Once this disease appears in a nursery, a 

conscientious clean-up and sanitation program is required. Avoid 

injury to the bark of established trees. Most infections of mature 

trees occur through wounds. Surgery of small cankers can 

prolong tree life. Clean out cankers during dry weather, paint 

with shellac, then with tree emulsion. Leave wounds exposed to 

air during summer. Do not cover with soil. 

Water early in morning to 

minimize the period of leaf 

wetness. 

Collect and dispose of leaves 

in the fall. 

Powdery Mildew (Microsphaera spp.): See General Disease Management: Powdery Mildew, Chapter 9. Information on the 

susceptibility of Cornus species to powdery mildew is included in Appendix C. 

Septoria Leaf Spot (Septoria spp.): Angular, greyish 

spots with dark purple margins appear on 

leaves. Black fungal fruiting bodies (pycnidia) 

may be seen in these spots in humid weather. 

Insects: 

Dogwood Sawfly (Macremphytus tarsatus): The larvae 

skeletonize the leaves of Cornus species, in 

particular C. racemosa and C. sericea. Look for 

the larvae on the underside of leaves. First 

instars are almost translucent yellow, while 

second instars appear to be covered with a 

chalky powder. The last instar is 2.5 cm long 

and is creamy-yellow with a black head and 

black spots. The larvae overwinter in decaying 

wood on the ground. Adult sawflies emerge 

the following spring. 



Apply at early bloom. Repeat 

every 7-14 days as needed. 



Management: Sawflies, Chapter 11. 

Rake up and burn, bury or 

compost fallen leaves. 



CORYLUS - HAZELNUT 

Diseases: 

Bacterial Blight (Xanthomonas arboricola pv. corylina): 

New buds and shoots are blighted and oneand 

two-year-old twigs may have sunken 

purple-brown cankers. Trees may be girdled 

and killed at the base of the trunk (crown) 

during the first 10 years. Tissue under the bark 

of cankers and infected crowns is reddishbrown. 

Leaves may have small (2-3 mm), 

angular, water-soaked spots that turn reddishbrown. 

Roots are seldom infected. 

Eastern Filbert Blight (Anisogramma anomala): 

Infected branches show up from July to 

September when leaves turn brown but remain 

on the branch. Oblong, raised bumps (fungal 

fruiting bodies) in relatively straight rows 

begin to form under the bark of infected 

branches in June. By August the bumps are 

white, football shaped structures that have 

broken through the bark. These fungal 

structures turn black as they mature in the fall. 

COTONEASTER 

Diseases: 


New growth wilts and turns black in the 

spring. The disease may occur at any time in 

propagation houses. It is common at the Coast. 

Dark Berry (Phytophthora cactorum): Berries turn 

brown to black and eventually shrivel up. 

Fire Blight (Erwinia amylovora): Flowers and new 

shoots wilt suddenly and turn brown. Dead 

leaves hang downward on affected twigs. This 

disease is rare at the Coast but common in the 

Interior. 

Scab (Venturia sp.): This fungus causes shedding of 

blossoms, and dark, blotchy spots on leaves 

and fruit. Diseased leaves can be curled and 

distorted. New infections can occur whenever 

there is a moderate to prolonged rainy period 




COPPER SPRAY 50: 300-900 g 

depending on tree size. Apply 

before fall rains, at ¾ leaf fall and 

before spring bud break. 

Maximum 3 applications per 

year. 

BRAVO 500: 6.72 L/ha 

COPPER SPRAY 50: 300-900 g. 

Apply from bud swell to bud 

break at 10-14 day intervals; up 

to 3 applications per year. Use 

low rate on small trees and high 

rate for large trees. 

FLINT 50WG: 140-280g/ha 

QUADRIS: 90 mL. From bud 

swell to bud break 

(approximately mid-March to 

mid-May), apply at 7-10 day 

intervals prior to disease 

development. 


See the Ministry’s Hazelnut 

Pest Management Guide. 

Protect trees from sunscald 

during the first few years. The 

bacterium infects through 

wounds, so disinfect pruners 

between cuts. Prune out 

infected branches 60-90 cm 

below lesions. ‘Barcelona’ is 

highly susceptible; ‘Du Chilly’ 

is susceptible; ‘Daviana’ is 

intermediate and ‘Hall’s 

Giant’ is resistant. 

If you see suspicious 

symptoms, contact the 

Ministry’s Plant Pathologist in 

Abbotsford. The CFIA has 

initiated the process to 

deregulate the disease. 

‘Daviana’, ‘Butler’ and ‘Ennis’ 

are highly susceptible; 

‘Barcelona’ is moderately 

susceptible; and ‘Willamette’ 

and ‘Hall’s Giant’ are 

resistant. Ornamental 

contorted hazelnuts are also 

susceptible. 

See General Disease Management: Bacterial Blight/Canker, Chapter 9. 

Infection can be reduced by 

mulching to prevent soil 

water splashing and by 

planting in sunny locations 

with good air circulation. 

See General Disease Management: Fire Blight, Chapter 9. 

Copper sprays applied for fire 

blight may also give some 

control of scab. 

Rake and burn, bury or compost 

fallen leaves and fruit. A similar 

fungus causes scab on other 

Rosaceae. See under MALUS – 

APPLE and CRABAPPLE. 



Insects: 

Cotoneaster Webworm (Athrips rancidella): The moth 

is blackish-brown with a 12 mm wingspan. 

Damage is caused in late May and June by 

chocolate-brown larvae, up to 12 mm long. The 

larvae skeletonize leaf surfaces, foraging from 

silken webs spun on foliage and twigs. Eggs 

are yellowish-red and laid in June and July. 

CRATAEGUS - HAWTHORN 

Diseases: 





Apply when leaves are opening in 

May, and in late July and August. 

Crop injury may occur. Test on a 

small area first, before spraying 

the entire crop. Do not spray 

during bloom to avoid bee kills. 

Fire Blight (Erwinia amylovora): See General Disease Management: Fire Blight, Chapter 9. 

Leaf Spot (Fabrea Blight) (Diplocarpon mespili 

(Entomosporium mespili)): This is the most 

serious disease of Crataegus in Coastal BC. First 

symptoms are small, angular, reddish spots on 

the upper side of leaves in spring and early 

summer. Defoliation occurs in mid-summer. 

Rust (Gymnosporangium spp.): Crataegus is a common 

host of saskatoon rusts (see under 

AMELANCHIER - SASKATOON). Cedar rust 

is not common on Crataegus in BC except 

where a susceptible alternate host, such as 

Juniperus communis hibernica (Irish Juniper) is in 

close proximity. Cedar-apple rust is not known 

to occur in the province. 

Scab (Venturia inaequalis): Black leaf spots and scab on 

fruit. 

Insects: 

Leaf Skeletonizer (Psorosina hammondi): A yellowishgreen 

larva, up to 12 mm long, feeds on leaves, 

leaving only the veins and a thin layer of tissue 

behind. 

Rose Leafhopper (Edwardsiana rosae): The rose 

leafhopper is a slender, whitish-winged, 

sucking insect, about 3 mm long. Eggs are laid 

in the fall and hatch in spring. The nymphs are 

pale in colour and have red eyes. They suck 

juices out of the leaves creating a mottled 

effect. Premature defoliation can result. 

Sawfly (Pear Slug) (Caliroa cerasi): Adult is a shiny 

black fly with four wings. Black slug-like 

larvae skeletonize leaves in summer. There are 

two generations per season. 

Tent Caterpillar (Malacosoma spp.): Damage starts 

after buds burst. 



DITHANE DG, M-45 or WSP 

80WP: 275-350 g 

PENNCOZEB 80WP: 275-350 g 

Apply when leaves unfurl in spring 

and every 7-14 days in wet weather. 

Dormant: 

Application of lime sulphur may 

help in control. 



No fungicides are specifically 

registered for this disease on 

hawthorn. The fungicides 

applied for leaf spot (see above) 

should give some control. 


Remove infested leaves if 

damage is minor. 


Management: Caterpillars and 

Moths, Chapter 11. 


compost fallen leaves to 

remove the overwintering 

fungus. 

Avoid growing hawthorns 

close to junipers. 



See under MALUS – APPLE 

and CRABAPPLE. 




See General Insect and Mite Management: Leafhoppers, Chapter 11. 

See General Insect and Mite Management: Sawflies, Chapter 11. 

See General Insect and Mite Management: Tent Caterpillars and 




CYDONIA - QUINCE 

Diseases: 




Fire Blight (Erwinia amylovora): See General Disease Management: Fire Blight, Chapter 9. 

Rust (Gymnosporangium clavipes): This rust fungus 

infects quince, apple, hawthorn, cotoneaster 

and saskatoon. Yellow-orange pustules (aecia) 

appear on lower side of leaves in summer. 

Juniper is the alternate host. See under 

AMELANCHIER and MALUS. 

Insects: 

Cherry Ermine Moth: See MALUS: Apple Ermine Moth. 

ERICA - HEATHER (see CALLUNA) 

EUONYMUS 

Diseases: 

Anthracnose (Colletotrichum gloeosporioides): This 

warm-weather fungus (optimum 25-30 o C) 

causes small leaf lesions with white, grey or tan 

centres and dark or reddish borders. Stem 

cankers are small, oval and may be raised and 

scabby. Larger cankers may girdle the stem 

causing dieback. Most common on E. japonica 

and E. fortunei (‘Canadale Gold’ is more 

susceptible than ‘Emerald ’n Gold’, which is 

more susceptible than ‘Emerald Gaiety’). 

No fungicides are registered for 

use on quince. 



Apply when new growth 

emerges and at 7-14 day 

intervals. Not a common disease 

in BC. Fungicides may be needed 

for control in Interior nurseries 

or in unusually hot weather at 

the Coast. 


Pick off infected leaves. Rake 

up and burn, bury or 

compost. New infections 

occur each year from infected 

junipers. Remove nearby 

junipers. 

Collect and burn, bury or 

compost crop debris. 

Space plants for good air 

circulation and time watering 

so plants dry quickly. Plants 

grown under shade have a 

lower incidence of the disease. 

Prune out infected branches if 

possible. E. japonica does not 

thrive with repeated pruning. 

Powdery Mildew (Oidium euonymus japonica): Green cultivar ‘Patens’ is very susceptible. Variegated cultivars are not 

usually affected. Water forcibly sprayed on foliage under fast drying conditions may reduce disease. See General 

Disease Management: Powdery Mildew, Chapter 9. 

FORSYTHIA 

Diseases: 


This bacterial disease causes dark black streaks 

on young shoots, often on one side of the shoot. 

Flowers wilt and turn brown. Buds are 

blackened. Infection occurs in cool, rainy 

weather in spring and fall. 

Stem Gall (Phomopsis sp.): This fungus causes 

nodular growths along stem and twigs. 

Multiple galls may cause reduction in vigour, 

or dieback of small twigs. 

FRAXINUS - ASH 

Diseases: 

Anthracnose (Discula sp. (Apiognomonia)): This 

fungus causes leaf blotches and marginal 

scorch in rainy springs. Premature leaf fall can 

occur. ‘Modesto’ ash is very susceptible and 

should not be grown in Coastal areas of BC. 

When buds start to open in 

spring apply: 


At fall leaf drop and in January 

apply: 



80WP: 275-350 g 


Begin at bud break and repeat 

every 7-14 days during wet 

weather. 

Improve air circulation. Prune 

out and destroy wilted shoots. 


Management: Bacterial 

Blight/Canker, Chapter 9. 

Cut off and destroy branches 

and canes that bare galls. 

Galls resemble those caused 

by crown gall bacteria, but are 

usually higher up in the bush. 

Control measures are 

warranted only when the 

disease occurs annually. Rake 

up and burn, bury or compost 

fallen leaves. 



Leaf Spot (Cercospora sp. and other fungi): Discrete 

leaf spots, generally smaller than anthracnose 

lesions and not on margins of leaves. Severe 

infections may cause premature leaf fall. 

Rust (Puccinia sparganoides): This fungus forms aecia 

on leaves of ash in Central and Eastern North 

America only. Not known to occur in BC. 

Insects: 

Ash and Lilac Borer (Podosesia syringae): It was first 

reported in BC in 2006, but is well established 

in the US. The adult is a clearwing moth that is 

similar in appearance to a paper wasp. It 

usually has a single generation per year. The 

female moth deposits her eggs in bark crevices 

within 10 to 14 days of emergence. Upon 

hatching, the larvae tunnel into the trunk and 

feed beneath the bark. The larvae do excavate 

galleries in the wood. The mature, 3 cm larvae 

overwinter inside the tree. Adult moths emerge 

the following spring. Infestations lead to 

unsightly scars and swollen areas on the trunk 

and, can weaken branches. Severe infestations 

can kill a tree. Hosts include European ash, 

privet, lilac and mountain ash. 

Fall Webworm (Hyphantria cunea): Branches may be 

defoliated by hairy caterpillars with black 

heads and pale yellow bodies with dark stripes 

along back. Webs are usually on tips of 

branches in late summer and fall. Moths are 

pale and 1.2 cm long. 

GLEDITSIA - HONEY LOCUST 

Insects: 

Honey Locust Plant Bug (Blepharidopterus chlorionis): 

The pest was detected in Oregon in 2008. It has 

one generation per year. Eggs hatch in early 

spring and the nymphs feed on new growth, 

causing stippling and leaf distortion. Adults 

also feed on leaves that can lead to defoliation. 

Honey Locust Pod Gall Midge (Dasineura gleditchiae): 

Pupae overwinter in the soil and adults emerge 

in the spring when new growth begins. The 

adult is a small fly (3 mm long). Eggs are laid 

in expanding leaflets and hatch in a few days. 

Larval feeding cause leaves to become globular 

or pod-like. The pods contain one or more 

whitish larvae. After 3-4 weeks of feeding, the 

larva pupates and an adult fly emerges. Galled 

leaflets may drop prematurely. Continued 

galling and defoliation may cause the death of 

small branches, but new growth often develops 

at the base of dead twigs. There may be three 

or more generations per year. 






Apply at spring bud break and 

repeat every 7-14 days as necessary. 

NOVA 40W: 25-34 g 

Apply every 10-14 days. 


Management: Bark Beetles and 

Woods Borers, Chapter 11. 

Pesticide sprays should be 

applied before eggs hatch. Use 

pheromone traps (isomate-P) to 

monitor for moth emergence. 

Spray 10 to 14 days following 

emergence. 

AMBUSH 500EC: 7 mL 

DIPEL WP: 62.5 g 

DIPEL 2X DF: 31 g 

ORTHENE 75% SP: Mist blower 

= 1,312 g/1,000 L; Hydraulic 

sprayer = 637 g/1,000 L 

POUNCE 384 EC: 9 mL 


HORTICULTURAL OIL (97%): 1 L 

Use to control the eggs. Since the 

eggs hatch within a couple of 

days, application timing is 

critical. Monitor expanding 

leaflets for red eggs in the spring 

(late March to early April) and 

spray when eggs are found. 




Fungicide treatment is rarely 

necessary. 

Water and mulch trees to 

reduce stress. Do not wound 

the trunk or main branches. 

Remove webs as soon as seen 

in mid-summer. 






HEDERA - ENGLISH IVY 




Diseases: 

Bacterial Leaf Spot (Xanthomonas hortorum pv. 

hederae): Leaf spots are usually angular with 

reddish margins and exhibit dark 

discolouration running into the veins. Petioles 

and stems may become black and shriveled. 

Grey Mould (Botrytis cinerea): See General Disease Management: Powdery Mildew, Chapter 9. 

Leaf and Stem Spots/Anthracnose (Phyllosticta / 

Colletotrichum spp.): Circular leaf spots, often 

with concentric rings and small, black fungal 

fruiting bodies. Entire leaves can wilt if lesions 

girdle stems. 

HYDRANGEA 

Diseases: 

Grey Mould (Botrytis cinerea): This common fungus 

causes browning of petals and a grey, fuzzy 

mould on flower clusters during wet weather. 

Leaf Spots (Cercospora and Septoria spp.): Small to 

large leaf spots containing tiny, black fungal 

bodies (pycnidia). Severe infections may cause 

leaf drop. 


80WP: 125-250 g 


Use low rate when treating soft, 

new growth or when repeated 

applications are planned. 

BOTRAN 75W: 175 g 

ROVRAL 50WP-WDG: 100 g 



Apply before blooming, since 

may discolour blooms. 


Avoid overhead watering. 

Pick off affected leaves when 

first spots appear. 


Remove infected plant parts if 

practical. Fungicides are 

rarely necessary in the 

landscape. 

Remove blooms after 

flowering. Infected flowers 

falling on leaves can lead to 

leaf and stem infections. 

Reduce humidity and improve 

air circulation. 

Pick off leaves as spots 

appear. Collect and destroy 

fallen leaves. Fungicides are 

rarely needed for control. 

Powdery Mildew (Erysiphe polygoni): Lower leaf surfaces become covered with a powdery, white growth; upper surfaces 

may be purple-brown. Blooms may be stunted & malformed. See General Disease Management: Powdery Mildew, 

Chapter 9. 

Sunscald: When bright sunny weather follows a 

prolonged dull period in late spring or early 

summer, large areas of leaves and shoots may 

wilt, develop a water-soaked appearance and 

finally turn grey to brown. 

ILEX - HOLLY 

Diseases: 

Green Algae: Green to black coloured algae coating 

on leaves, twigs, branches and trunk. 

Leaf and Twig Blight (Phytophthora ilicis): Black 

blotches and rot of leaves and petioles, 

followed by leaf drop, starts on lower branches 

in late fall and progresses upward during cold, 

rainy weather in winter. Symptoms are usually 

observed in January. Twig cankers and berry 

rot may also occur. 


80WP: 180-250 g 

MANZATE DF & PRO-STICK: 

180-250 g 


Apply at any time during the 

growing season. Do not apply 

close to harvest as visible residue 

may make holly unmarketable. 


80WP: 180-250 g 


Apply in the fall before the onset 

of fall rains. Avoid application 

close to harvest to avoid visible 

residue. 

Provide temporary shade or 

misting during sudden hot 

spells that usually occur in 

June. 

Prune to increase air 

circulation. 

Prune out diseased 

branches and remove 

fallen leaves and plant 

debris, where practical. 



Web Blight (Rhizoctonia solani): A white web of 

fungal threads (mycelium) appears on leaves, 

blooms and stems. Affected parts may rot and 

drop. 

Insects: 

Bud moth (Rhopobota naevana): This moth is long (6 

mm) and grey to mottled-brown in colour. The 

larvae are dark olive-green with black heads. 

They produce silk that rolls the leaf for 

protection. Opening buds are primary targets. 

Eggs are laid on the underside of leaves. 

Overwintering eggs hatch in May. There can be 

two generations per year. 

Holly Leafminer (Phytomyza ilicis): This greyish-black 

fly is 12 mm long. Yellow maggots tunnel in 

leaves of I. aquifolium, leaving blotches that 

make the holly unmarketable. The eggs are laid 

in late May when trees are flowering. 

Holly Scale (Aspidiotus britannicus): Scales are light 

brown, oval, 12 mm across, with white, oblong 

egg sacks. This insect causes yellow leaf 

spotting and much honeydew. Black, sooty 

mould grows in abundant honeydew. 

Lecanium Scale (several species): Large, wrinkled, 

semi-circular scabs attach to leaves, twigs and 

fruit. Crawlers are present mid-July to late 

August. They produce much honeydew and, 

thus, black sooty mould. 

JUGLANS - WALNUT 

Diseases: 

Anthracnose (Gnomonia leptostyla; anamorph 

Marssonina juglandis): This fungus causes leaf 

spots and lesions on stems of new shoots. Stem 

lesions are sunken, greyish-brown with red 

margins. Spots also occur on husks. Nuts drop 

early or do not develop. 

Bacterial Blight (Xanthomonas arboricola pv. juglandis): 

Small, irregularly-shaped black spots appear 

on leaves and petioles. Later the spots enlarge. 

Black spots appear on husks and slimy decay 

destroys the nuts. 

JUNIPERUS - JUNIPER 

Diseases: 

Magnesium Deficiency: Damage is similar to that 

caused by Phomopsis (see Twig Blight and 

Dieback, below). Magnesium deficiency 

produces chlorotic or dead foliage in the centre 

of the plant, but seldom kills it. 







Disease appears only 

under very wet conditions. 

Reduce humidity and 

prune or space containers 

to improve air circulation. 

Increase greenhouse 

ventilation. 

See General Insect and Mite Management: Leafminers / Needle 



Dormant: 

SMOTHER-OIL: 3.5 L 

Apply in spring before buds open. (Check label carefully as 

some dormant oils can be phytotoxic.) 

See General Insect and Mite Management: Lecanium Scale, 

Chapter 11. 


Up to 4 applications per year. 

KASUMIN 2L: 5 L/ha 

EPSOM SALTS: 1-2 kg foliar 

spray will give fast but shortlived 

results. 


leaves and nuts. Prune off 

infected branches, if 

possible. 

Cut out diseased twigs 

and branches, if possible. 

On acid soils, use dolomite 

lime on a regular basis. 

Aim for a soil test with a 

calcium to magnesium 

ratio of 6-8:1. 



Pear Trellis Rust (Gymnosporangium fuscum): On 

junipers, symptoms consist of spindle-like 

swellings on twigs that produce orange, 

gelatinous spore masses in spring. On pears, 

symptoms consist of orange to red blotches on 

the leaves. This disease is believed to be 

confined to the Lower Mainland and 

Vancouver Island south of Duncan. (See under 

PYRUS.) For other rusts occurring on juniper, 

see under AMELANCHIER and Appendix P. 

Root Rot (Pythium/Phytophthora spp.): Recumbent 

junipers are very susceptible to root rot. Foliage 

develops a light-green cast and gradually turns 

brown. Growth is poor. Bark at and below the 

soil line is dark brown and becomes punky. 

Roots are usually already decomposing by the 

time foliar symptoms are noticed. Foliage may 

be affected by twig blight pathogens (see 

below). 

Twig Blight and Dieback (Phomopsis juniperova, 

Kabatina juniperi, Lophodermium spp., Cercospora 

spp., Sclerophoma spp. and Coniothyrium spp.): 

Affected branch tips turn brown and 

progressively the entire branch may die. These 

fungi are often more damaging to winterinjured 

or drought-stressed plants, or plants 

affected by root rot or insect/rodent feeding. 

Insects: 

Cypress Tip Moth (Leafminer) (Argyresthia 

cupressella): Adults, small (6 mm), silvery-tan 

moths, are active in early June. Eggs are 

inserted into the green tips of one- and twoyear-old 

twigs. Larvae tunnel into the leaf scales 

and remain there until the next spring. Infested 

twigs become yellow then brown in late winter. 

A cocoon is spun around the foliage in early 

June of the second year for the pupal stage. Two 

to three weeks later, adults emerge. 

Juniper Scale (Carulaspis juniperi): Heavy infestations 

cause grey or yellowish foliage colour. Plants 

may die whole or in part. A black, sooty mould 

may grow on the honeydew secreted by the 

round, light-coloured scales. 





80WP: 280-350 g 

EAGLE WSP T&O: 30 g 


Apply every 14 days; maximum 

6 applications per year. 


Unless you are in a completely 

disease-free area, all nursery 

junipers should be sprayed at 

least 3 times each fall between 

late August and late October. 



80WP: 275-350 g 


If needed, apply from April to 

early June to protect new growth. 

MALATHION 500E: 250 mL 

May injure Juniperus sabina. 

No insecticides will kill the 

larvae while they are inside the 

foliage, so timing of sprays is 

important. Spray infested trees 

when the larvae emerge to form 

cocoons in late April, and when 

eggs hatch in mid-June and again 

in early July. 


Apply in early June and repeat 

14 days later when crawlers are 

present. 


Obtain cuttings from 

known, certified sources. 

See British Columbia Plant 

Protection Regulations, 

Chapter 2, for details 

about shipping out of an 

infected area. Avoid 

planting ornamental pears 

in infected areas and do 

not plant junipers within 

30 m of pear trees. 

Do not plant junipers in 

wet, heavy or poorly 

drained soils in either the 

nursery or landscape. 

Avoid excessive irrigation. 

Root rot is common on 

steep banks subject to 

drought in summer and 

excessive moisture in 

winter. Do not allow 

containerized plants to 

stand in water. Junipers 

differ in their 

susceptibility to root rot. 


Management: Root Rots 

Caused by Phytophthora and 

Pythium, Chapter 9. 

Select cuttings only from 

disease-free mother plants. 

Prune out dead branches 

or remove severely 

infected container plants 

to reduce spread of 

infection. 


Management: Scales, 

Chapter 11. 



Juniper Webworm (Dichomeris marginella): Twigs and 

needles become webbed together, and some 

turn brown and die. The larva is 12 mm long, 

brown with reddish stripes. The adult appears 

in June and lays eggs that hatch about 2 weeks 

later. Larvae feed on the foliage during the rest 

of the season, overwinter and do the greatest 

amount of damage the following spring. 

Red Cedar Bark Beetle (Phloesinus sequoia): The small 

adult beetle lays eggs in narrow excavations in 

the bark. As the grubs hatch, they bore out 

sideways making a characteristic pattern of 

galleries. This insect is most likely to attack 

newly transplanted and drought-stressed trees. 





Spray when insects first appear. 

Repeat in 3 weeks, if necessary. 

Use high pressure to ensure 

complete coverage. 

Root Weevils: See General Insect and Mite Management: Root Weevils, Chapter 11. 

KALMIA - MOUNTAIN LAUREL 

Diseases: 

Leaf Spot (Cercospora sp. and other fungi): Leaves 

exhibit irregularly-shaped to circular, lightgrey 

spots with a purple-brown border. Leaves 

may drop early. 

Insects: 

Lecanium Scale (several species): These scale insects 

attack a very wide range of woody plants. 

Large, wrinkled, semi-circular scales can be 

seen on leaves, stems, twigs and fruit. They 

produce much honeydew on which grows 

abundant black sooty mould. 

Root Weevils: Larvae chew on roots causing wilt and 

dieback of branches and browning of foliage. 

Adult weevils chew on leaves leaving 

unsightly notches. 

LIGUSTRUM - PRIVET 

Diseases: 

Leaf Spot (Cercospora and Pseudocercospora spp.): 

Yellow to brown leaf spots, depending on the 

fungal species. Spots often have a yellow halo. 

Can cause early leaf drop. Mainly in Eastern 

North America. Not known to occur in BC. 




Management: Scales, Chapter 11. 


Keep trees vigorous and 

prevent stress. 

Rake and burn, bury or 


Avoid overhead irrigation. 

These scales are often 

parasitized by beneficial 

organisms. If the level of 

parasitism is high, do not 

apply insecticides. 

See General Insect and Mite Management: Root Weevils, Chapter 

11. 


DACONIL 2787WDG: 140 g 

Apply every 7-14 days under 

prolonged wet conditions. 


compost fallen leaves and 

plant debris. 

Powdery Mildew (Oidium sp.): White, powdery growth on leaves. See General Disease Management: Powdery Mildew, 

Chapter 9. 

LONICERA- HONEYSUCKLE 

Diseases: 

Honeysuckle Blight (Insolobasidium deformans 

(Herpobasidium deformans; Glomopsis lonicerae): 

Leaves develop interveinal chlorosis and 

necrosis, and become crinkled, cupped or 

twisted. Shoot blight may also occur. White 

fungal growth develops on the underside of 

leaves. Worse in cool, wet, rainy, weather. 

DITHANE DG: 200 g 

MANZATE DF & PRO-STICK: 200 g 

Apply at green tip to ½ inch 

green leaf. No more than 3 

applications per year. 

Remove honeysuckle from 

around nurseries. Space 

plants for good air 

circulation and water early 

in the day. Remove plant 

debris before bud-break. 

Resistant varieties may be 

available. 







Powdery Mildew (Microsphaera spp.): White, powdery growth on leaves. See General Disease Management: Powdery 

Mildew, Chapter 9. 

MAGNOLIA 

Diseases: 


New shoots wilt and blacken. Leaves exhibit 

dark, irregular spots, often with yellow haloes. 

Also causes twig and branch dieback. 

MAHONIA - OREGON GRAPE 

Diseases: 

Leaf Spot/Anthracnose (Phyllosticta spp./ 

Gloeosporium berberidis): The Phyllosticta fungus 

causes small red, circular spots that later 

become tan coloured in the centre. Anthracnose 

is characterized by larger lesions, often at the 

margins of leaves. Both diseases may occur 

together. 

Rust (Cumminsiella mirabilissima): Large spots on 

leaves become swollen and break open to 

release spores. This disease is very common at 

the Coast but is not serious except in unusually 

wet seasons. 

MALUS - APPLE and CRABAPPLE 

Diseases: 

Anthracnose Canker (Cryptosporiopsis curvispora): 

This destructive disease of apples in Coastal 

areas has also been found in the Kootenays and 

North Okanagan. Infection of new bark occurs 

in fall and causes small, red spots that lengthen 

and crack open the following spring forming 

“stringy” cankers. Large, girdling cankers kill 

entire branches. The fungus also causes a 

“bull’s eye” fruit rot. 

Fungicides applied for rust (see 

below) should also help to 

control leaf spot and 

anthracnose. 



SULPHUR (DOMESTIC): 0.4-0.9% 

liquid or other formulations. See 

label for rates and application. 

Cankers: 

Fungicides are generally 

ineffective in preventing spread 

of cankers. No products are 

specifically registered for control. 

Bull’s eye fruit rot: 

CAPTAN 50-WP: 6 kg/ha 

CAPTAN 80-WP: 3.75 kg/ha 

Apply if rainy periods occur 

before harvest. Do not apply 

within 7 days of harvest. 

Prune out and destroy 

infected shoots and 

branches in the dormant 

season and again if 

infection occurs in the 

spring. Space plants to 

provide good air drainage. 



Blight and Canker, Chapter 

9. 

Remove and destroy 

infected leaves. Avoid 

overhead irrigation. 


infected leaves if practical. 

Protect new leaves. Avoid 

overhead irrigation in the 

latter part of the day. 


severely affected trees. 

Prune out and burn all 

cankers and infected twigs 

in winter or whenever 

they are found in the year. 

Isolate susceptible stock 

from older infected apple 

trees to help prevent new 

infections. 

Bull’s eye rot appears in 

storage although fruit is 

infected before harvest. 

Fungicides are not usually 

needed if good pruning 

and cultural practices are 

followed. 



Blister Spot (Pseudomonas syringae pv. papulans): 

Occurs on ‘Mutsu’ and ‘Fuji’. Light spotting on 

‘Jonagold’. Spots on fruit start as small, green, 

water-soaked blisters, which later darken and 

expand to 4-5 mm in diameter. Leaves may 

exhibit a mid-vein necrosis and be curled and 

puckered; or have white to brown spots. 

Bacteria spread in water and overwinter in 

buds, leaf scars and fallen fruit. Fruit are 

susceptible to infection for about six weeks, 

starting about two weeks after petal fall. 

Crown Gall/Hairy Root (Agrobacterium tumefaciens / 

Agrobacterium rhizogenes): Large, warty or hairy 

growths appear on roots, crowns and stems. 

Galls on mature apples can be mistaken for 

physiological “burrknots” or wound callus. 

The bacteria spread in soil and drainage water 

and carry over in soil for many years. M9 and 

M26 rootstocks are susceptible to crown gall. 

Crown and Root Rot (Phytophthora cactorum): This 

soil-borne organism invades crowns of 3- to 10- 

year-old trees. Eventually, the trunk is girdled 

just below ground level and the tree dies. First 

indication of infection may be off-colour foliage 

in late summer. The problem is most serious on 

irrigated land in the Okanagan. 

European Canker (Nectria galligena): Causes severe 

damage to apple and pear trees at the Coast. 

Twigs and branches wilt and die back above 

cankers. First-year cankers have blistered, 

yellowish bark. Second-year cankers develop 

deeply sunken edges with concentric rings. 

Red fungal bodies (perithecia) may be visible at 

the edge of cankers in fall. Most infections 

occur through leaf scars during fall rains but 

infections can occur whenever wounding and 

rainfall or irrigation coincide. 

Fire Blight (Erwinia amylovora): M9 or M26 rootstock 

combined with ‘Braeburn’, ‘Fuji’ or ‘Gala’ are 

particularly susceptible to crown infection, 

although it can also occur with other rootstocks. 

Perennial Canker (Cryptosporiopsis perennans): Fungal 

cankers consist of overlapping concentric rings 

of woody tissue. Each year the canker enlarges, 

gradually girdling the limb or trunk. This 

disease is common in the Okanagan but rare in 

Coastal areas. Causes “bull’s-eye” rot on fruit. 

Very similar to anthracnose. 




ALIETTE WDG: 2.5 kg/ha 

Start at petal fall and repeat at 7 

day intervals. Maximum 3 

applications per year; no more 

than 10 kg/ha before harvest. 

BORDEAUX MIXTURE: 100 g 

COPPER 53W + 600 g 

HYDRATED LIME 

Start applying 10 days after calyx 

and repeat at 10 day intervals. 

Do not apply either product 

within 30 days of harvest. 

No effective chemical control. 

DYGALL (A. radiobacter) root dip 

is not registered for use on 

apples because it has been shown 

to be generally ineffective in 

preventing infection of this crop. 

Orchards - foliar or drench: 

ALIETTE WDG: Rate varies with 

tree density. Read label carefully. 

Drench: 

RIDOMIL GOLD: 1 mL/5 L of 

water/tree 

In Coastal areas, BORDEAUX 

MIXTURE as for fire blight, 

applied twice at leaf fall, may 

help reduce spread of cankers. 


The disease is worse in 

years when very wet 

weather occurs while 

green fruit are sizing. 

Follow good pruning and 

tree care practices; 

disinfect pruners between 

cuts. Remove fallen 

(windfall) fruit and bury 

or compost. 


Management: Crown Gall, 

Chapter 9. 

Nursery stock should be 

planted in disease-free soil. 

For propagation, avoid 

soils and irrigation water 

with a history of crown rot. 

M4, M9 and and M26, and 

M2 to a lesser extent, are 

more resistant than other 

commonly-used rootstocks. 

The disease is worse in 

very wet years. Prune out 

infected branches below 

cankers and burn or bury. 

The fungus can continue 

to produce spores on dead 

wood. 

Nurseries: Destroy 

infected trees. Old infected 

apple and pear trees near 

the nursery should also be 

destroyed. 


Bull’s eye fruit rot: 

CAPTAN 50-WP: 6 kg/ha 

CAPTAN 80-WP: 3.75 kg/ha 

MAESTRO 80DF: 3.75 kg/ha 

Cankers: 

Research suggests fungicides are 

generally ineffective in 

preventing spread of cankers. No 

fungicides are specifically 

registered. 

Control the woolly apple 

aphid that can spread the 

disease. Prune out cankers 

whenever possible. 



Powdery Mildew (Podosphaera leucotricha): The 

fungus overwinters in terminal buds. Greyishwhite 

fungus appears in felt-like patches on 

leaves, twigs, blossoms and fruit. Leaves 

become curled and distorted. 

Rust (Quince Rust, Gymnosporangium clavipes): Causes 

yellow to brown spots on upper surface of 

leaves. Fungal fruiting bodies (aecia) form on 

lower surface in summer. Alternate hosts are 

junipers. Cedar-apple rust infects trees in 

eastern North America, but is not known to 

occur in BC. 

Usually a minor disease west of the Rockies, 

not requiring control. Remove junipers from 

the vicinity. 

Scab (Venturia inaequalis): This disease causes 

shedding of blossoms and scab on leaves and 

fruit. Scabs begin as water-soaked spots that 

become velvety-green, then brown and dead. 

Diseased leaves can be curled and distorted. 

New infections may occur whenever there is a 

moderate to prolonged rainy period. 

Viruses: 

Several viruses occur in apples, some causing little 

noticeable effect unless combined during 

budding or grafting. Virus-free propagating 

material is more vigorous than infected stock 

and gives a much better success rate. 






For a list of resistant crabapple varieties, see Appendix D. 

FERBAM 76 WDG: see label for rates. May cause fruit 

russeting on ‘Golden Delicious’, ‘Jonathan’ and some other 

varieties (see label). 

DITHANE DG, M-45 or WSP 80WP: 150-200 g 

INSPIRE: 292 mL/ha 

MANZATE DF & PRO-STICK: 5-6 kg/ha 

PENNCOZEB 75DF & 80WP: 150-200 g 

POLYRAM DF: 4.5-6 kg/ha 

Flowering crabapple: 




Apply every 10-14 days. No more than 6 applications per year. 

Protect new growth starting at 

pink-bud stage. Apply fungicide 

at least twice, 10 days apart. Use 

the higher rate for early sprays 

and the lower rate for later cover 

sprays or when disease pressure 

is low. 

Rake and burn, bury or 

compost fallen leaves, if 

practical. Grow scab 

resistant varieties. For 

resistant crabapples see 

Appendix D. 

Refer to the Ministry’s Tree Fruit Production Guide for 

additional chemical control options. 


COMPASS 50WG: 14-17.5 g 




EQUAL 65 WP: 1.08-2.25 kg/ha 



KUMULUS DF: 400-750 g 


PENNCOZEB 75DF & 80WP: 150-200 g 

POLYRAM DF: 4.5-6 kg/ha 

PRISTINE WG: 1.0 kg/ha 

SULPHUR (DOMESTIC and COMMERCIAL): See labels. May 

cause fruit russeting at high temperature. 

Use virus-free rootstocks 

and budwood. 




Apple Ermine Moth (Yponomeuta malinella): The moth has a 10-12 

mm wing span, is white with many black spots on the wings 

and appears from June to August. Each female lays 10 or 

more eggs in one batch and covers them with a substance that 

dries into a hard flat scale about three to four mm in diameter 

and the colour of the bark. When eggs hatch the young larvae 

remain under the scale (called a hibernaculum) until the 

following spring. When the larvae emerge, they make a small 

tent and feed on leaves of apple and hawthorn. 

Apple Maggot (Rhagoletis pomonella): The larval stage 

damages apples and other fruit by tunnelling 

through them. The principal hosts are apple, 

crabapple and hawthorn trees, however it also 

occasionally attacks plum, cherry, peach and 

pear trees. The maggot was found for the first 

time in BC in 2006. 

Apple and Thorn Skeletonizer (Eutromula pariana): 

Monitor for caterpillars 2-3 weeks after leaves 

open. 

Codling Moth (Cydia pomonella): The pinkish-white 

larvae overwinter in cocoons under loose bark, 

in the soil or in trash at the base of trees. Larvae 

pupate in spring and adults emerge in May 

and June. Female moths lay eggs on fruit or on 

leaves near fruit. Soon after emerging, the 

larvae bore deep into the fruit. Up to 3 

generations in a year. 




CYMBUSH 250EC: 400 mL/ha 

DIAZINON 50WSP: 100 g 

DIAZINON 50EC: 100 mL 

IMIDAN 50-WP: 3.75 kg/ha 

RIPCORD 400 EC: 7.5 mL 

SURROUND WP: 25-50 kg/ha 



Management: Caterpillars 

and Moths, Chapter 11. 

Malus stock must be 

certified free from this pest 

to be shipped out of BC. 

See Federal Plant 

Quarantine Regulations: 

Comment 7, Chapter 2. 

Apple maggot is a 

quarantine pest in Canada, 

and regulatory controls 

are in place to prevent 

spread from the Lower 

Mainland and Vancouver 

Island. See Federal Plant 



See General Insect and Mite Management: Caterpillars and Moths, 

Chapter 11. 

AMBUSH 500 EC: 400 mL/ha 

DIAZINON 50EC: 100 mL 

DIAZINON 50WSP: 100 g 

CONFIRM 240F (crabapple): 33-60 mL 


DECIS 5EC: 6.8-8.5 mL 



POUNCE 384 EC: 17.5 mL 


Apply bands of corrugated 

cardboard to the trunk and 

scaffold limbs in early 

August to collect mature 

larvae exiting the fruit. 

Remove and burn the 

bands after harvest. Pick 

and crush infested fruit. 

Forest Tent Caterpillar (Malacosoma disstria): See General Insect and Mite Management: Caterpillars and Moths, Chapter 11. 

Leafrollers (several species): These insects are leaf 

and fruit feeders. Deep holes that scab over are 

produced on the fruit. The larvae are green 

with black heads. They drop on a silk thread 

when disturbed. 

AMBUSH 500 EC: 400 mL/ha 

DIAZINON 50EC or 50WSP: 100 mL or 100 g 


DECIS 5 EC: 6.8 mL 

DIPEL WP: 2.25-3.35 kg/ha 

DIPEL 2X DF: 1.125-1.675 kg/ha 

DOKTOR DOOM: 60-480 mL/0.4 ha 

FORAY 48BA: 2.8-4.0 L/ha 


MALATHION 500E: 180-250 mL 

POUNCE 384 EC: 17.5 mL 



SURROUND WP: 25-50 kg/ha 

Dormant only: 

SUPERIOR 70 OIL: 2 L 

Oyster Shell Scale: See General Insect and Mite Management: Scales, Chapter 11. 

Pearleaf Blister Mite (Phytoptus pyri): Green blisters 

occur on leaves, later turning brown and 

drying up. Mites also attack developing fruit 

causing russeting and deformity. 

DIAZINON 50WSP: 150 g + 1 L 

of Horticultural Oil 

True dormant stage only: 

LIME SULPHUR 23%: 10 L 


Management: Mites, 

Chapter 11. 







San Jose Scale: Only occurs in the South Okanagan but can be very damaging when present. See General Insect and 

Mite Management: Scales, Chapter 11. 

Woolly Apple Aphid (Eriosoma lanigerum): Aphid DIAZINON 50EC: 50-100 mL 

feeding results in nodular swellings or galls. DIAZINON 50WSP: 50-100 g 

The perennial canker fungus can infect injured DECIS 5 EC: 6.8 mL 

tissue (see above). The aphid can be detected INSECTICIDAL SOAP 25%: 5 L 

by the cottony white masses it forms around IMIDAN 50-WP: 3.75 kg/ha 

pruning cuts, water sprouts and leaf axils. POUNCE 384 EC: 9 mL 

PHOTINIA 

Diseases: 

Leaf Spot (Fabrea Blight) (Diplocarpon mespili 

(Entomosporium mespili)): Small, dark, reddish 

spots appear and coalesce to form blotches on 

the leaf surface. Defoliation can occur if 

infection is severe. 

PICEA - SPRUCE 

Diseases: 

Botrytis Blight (Botrytis cinerea): Affects spruce, fir, 

hemlock and cedar. Causes seedling blight in 

greenhouses and container nurseries. Under 

cool, moist conditions branches die and become 

covered with a web of grey fungal mycelium. 

Botryosphaeria Canker and Dieback (Botryosphaeria 

sp.): Botryosphaeria causes disease on stressed 

plants. It overwinters on plant debris and on 

healthy bark and leaves. It enters plants 

through wounds or natural openings. Infection 

leads to the development of cankers that result 

in wilting and branch dieback. 

Cytospora Canker (Cytospora kunzei): Rain-splashed 

spores infect through wounds and develop 

cankers at the base of the trunk or twigs. 

Branches near the ground may die. Cankers are 

often not visible on the bark; you must cut into 

the bark to expose the diseased tissue. Fruiting 

bodies of the fungus (small black dots) may be 

seen on the canker. 

Needle Cast (Rhizosphaera kalkhoffi): Small yellow to 

greyish-green mottled spots, which later turn 

purplish-brown, appear on current year needles 

of lower branches. Infected needles turn colour 

and fall about one year after infection. Long 

periods of wet foliage and warm temperatures 

promote the disease. P. pungens (blue spruce) is 

particularly susceptible. 

Rust (Chrysomyxa spp.): Rust pustules appear as 

white blisters on the lower surface of needles. 

Affected needles turn yellow and may drop 

prematurely. Spruce cone rusts can also be a 

problem in seed orchards. 

Greenhouse only: 

IMPOWER 60WP: see label for rate and application. 



Application of fungicide at bud 

break and again one week later 

will provide some control. 




See General Disease Management: Botrytis Blight / Canker, Chapter 9. 

Ensure plants are healthy 

and, avoid plant stress 

and injury. Follow 

appropriate sanitation 

practices (e.g. prune out 

dead wood, collect and 

dispose of leaf debris). 

Control weed growth and 

remove lower branches to 

improve air circulation at 

the base of the tree. 

BANNER MAXX: 35 mL (for use on Christmas trees only) 

BRAVO Ultrex 90 SDG: 5.2 kg/ha 

COPPER SPRAY 50: 400 g; apply under fast drying conditions 

to avoid needle damage. 

DACONIL 2787F: 9.5 L/ha 

DACONIL Ultrex: 5.75 kg/ha 

FLINT 50WG: 210g/ha 

Avoid shearing infected trees when the foliage is wet. 



Rusts are not common on 

spruce, but can often be 

controlled by removing 

the alternate host from the 

area (usually a native 

broad-leaved shrub). 



Sydowia Blight/Tip Blight (Sclerophoma spp.): Usually 

a secondary fungus growing on needles 

damaged by other factors, but can cause 

dieback of new shoot tips on P. pungens. Black 

fungal bodies are abundant on new needles. 

Shoot tips become distorted and brown. 

Seedling Blight (Sirococcus conigenus): Death of 

young shoots (tipblight) on spruce and 

hemlock. Shoots often curl to form a “hook”. 

Causes seed decay and seedling blight on pine, 

spruce, hemlock, fir and occasionally Douglas 

fir. Dead seedlings remain upright and needles 

die from the bases upward. Black fungal bodies 

(pycnidia) sporulate on dead tissue and cone 

scales. The fungus is seed-borne. 


Cooley Spruce Gall Adelgid (Adelges cooleyi): The 

insect attacks both spruce and Douglas fir. The 

adult female overwinters on bark near terminal 

buds and lays eggs in the spring. The crawlers 

that emerge from the eggs move to the base of 

needles on the new shoot and begin to feed. 

Adelgid feeding causes shoot tips to develop 

into cone-like galls (1.2-5.0 cm long). In the 

summer, the cones turn brown and open, 

releasing adelgids. 

Hemlock Woolly Adelgid (Adelges tsugae): This 

sucking insect appears as white, cottony puffs 

on the bark and base of needles. Infestation 

often leads to the production of abundant 

black, sooty mould. Premature needle drop 

may occur. 

See Comment 30 in Federal Plant Quarantine 

Regulations in Chapter 2. 

Sitka Spruce Weevil (Pissodes stobi): Adult weevils 

are reddish-brown and 5-7 mm long. Larvae 

are legless, creamy white with brown heads 

and up to 7 mm long. In the spring, adults lay 

eggs in the bark of the leader. Larvae feed 

under the bark causing the new terminal to 

wilt, droop and die. Young trees can be killed. 

Spruce Aphid (Elatobium abietinum): This small, dull 

green, sucking insect causes older needles to 

turn brown and drop. The tree may be killed if 

attacked two to three years in a row. 





Apply when new growth starts 

in spring and repeat at 10-day 

intervals. May cause needle 

spotting if applied under cool, 

cloudy conditions. 

BRAVO Ultrex 90 SDG: 2-3.3 

kg/ha 

DACONIL 2787F: 3.6-6.0 L/ha 

DACONIL Ultrex: 2.9-3.6 kg/ha 

See application instructions 

above for Needle Cast. 

ACECAP 97: Apply when 

wingless, crawler forms are first 

seen in spring. For rate, see label 

or General Insect and Mite 

Management: Aphids, Chapter 11. 

INSECTICIDAL SOAP 47% or 

50.5%: 2 L 

THIONEX EC : 125-175 mL 

THIONEX 50 W: 100 g 


50.5%: 2 L; spray after May 1 

LANDSCAPE OIL: 1-2 L to 

control eggs, nymphs and adults 

on Picea jezoensis and P. polita 


Management: Woolly Adelgids, 

Chapter 11. 

CYGON 480-ORN or LAGON 

480 E: 2.5 L 

Thoroughly spray terminal to 

run-off at time of egg laying. 

DURSBAN WSP: 33.6 g 

PRO DURSBAN TURF: 37.5 mL 


50.5%: 2 L 

PYRATE 480EC: 37.5 mL 

Apply as soon as aphids appear 

in February. 


IMPOWER 60WP: See label. 


Infection often follows 

winter damage to young 

growing shoots. 


Management: Sirococcus 

Blight, Chapter 9 for more 

information on controlling 

seed and seedling disease. 

Monitor from late October 

to April if there has been a 

problem with galls in 

previous years. Remove 

and destroy green galls as 

soon as they appear. 

Nitrogen fertilization has 

been shown to enhance 

adelgid survival and 

negate pest control 

measures. If this insect is a 

problem, reduce nitrogen 

fertilization as much as 

possible. 

Clip and destroy wilted 

leaders as they appear. 

If not controlled, needles 

may drop in May-June. 

Early treatment is 

essential. 



Spruce Budworm (Choristoneura fumiferana) and 

Other Caterpillars: This budworm affects 

spruce, balsam fir, Douglas fir, pine, hemlock 

and larch. The caterpillar, which is dark 

reddish-brown with yellow stripes, chews on 

opening buds and needles. 

Spruce Spider Mite (Oligonychus ununguis): Needles 

become yellow and covered with a silky 

webbing. Mites are pale green when young and 

darken with age. They overwinter as eggs on 

twigs and needles. This mite also attacks 

Juniperus, Thuja and Tsuga. 

PIERIS - ANDROMEDA 

Diseases: 

Dieback and Root Rot (Phytophthora spp.): This 

organism infects roots and causes root decay. 

Plants eventually die. Leaves may also be 

infected. 

Phomopsis Blight (Phomopsis amygdali): Phomopsis 

blight is a new disease that causes stem cankers, 

shoot dieback and blight symptoms on Pieris. 





See General Insect and Mite Management: Spruce Budworm, 

Chapter 11. 

VENDEX 50W: 50-100 g 

Apply in June or August as 

necessary. 

Dormant spray: 



AVID 1.9% EC: 30 mL 

Insects: 

Andromeda Lace Bug (Stephanitis takeyai): See Lace Bugs, Chapter 11. 

PINUS - PINE 

Diseases: 

Needle Cast (Lophodermium seditiosum): In BC, only 

the short-needled varieties of Scots pine are 

normally damaged. Most infections occur in 

late summer on new needles. Distinct spots 

appear on needles during the winter and 

following summer. Large, black, elliptical, 

fungal bodies appear in needle spots. Infected 

needles then turn yellow and brown and drop. 

Severely affected trees normally have at least 

one season’s needles attached at any time. On 

occasion, however, even these needles yellow 

and fall leaving the tree almost bare. 

Foliar dieback: 



Apply at new leaf emergence. 

Root rot: See General Disease 

Management: Root Rots Caused by 

Phytophthora and Pythium, 

Chapter 9. 

At the end of July, end of 

August and the end of 

September apply: 

BRAVO Ultrex 90 SDG: 1.3-2.7 kg/ha 


May cause needle spotting; apply 

in fast-drying conditions. 

DACONIL 2787F: 2.4-4.8 L/ha 



80WP: 250 g 

PENNCOZEB 80WP: 250 g 

In dense plantings, and those 

with a history of needle cast, 

begin 2 weeks earlier and 

continue applications into 

October. 



Chapter 11. 

Practice good sanitation in 

propagation. Avoid heavy, 

wet soils and areas where 

other species have died 

out as a result of 

Phytophthora infection. 

Container plants should 

have good drainage within 

and below the pot. 

Space plants for good air 

circulation. Pines normally 

shed old needles and 

needle-shed can be more 

severe after dry summers. 

Other Lophodermium spp. 

(which produce similar 

black, elliptical fungal 

bodies on needles), and 

other fungi often invade 

dead and dying needles, 

but do not cause disease. 



Needle Cast (Cyclaneusma minus): Premature cast of 2 

and 3-year old needles. Brown bands on 

yellowing needles appear in late summer/fall. 

White fungal fruiting bodies develop within 

the bands about one month later. These release 

spores in winter and early spring which cause 

new infections, although needles will not show 

symptoms until fall. 

Needle Cast (Lophodermella spp.): Needles turn 

reddish-brown in spring then straw-coloured. 

Fungal fruiting bodies, usually black but 

sometimes colourless, appear on the infected 

needles. Spores cause new infections from bud 

break until new growth ceases, in periods of 

wet weather. 

Needle Cast (Elytroderma deformans): Affects only 2- 

and 3-needled pines, mainly ornamentals. 

Needles turn reddish-brown in spring fading to 

tan or grey in fall before dropping. Black, 

elongated, fungal fruiting bodies develop on 

infected needles in summer and release spores 

in the fall, or the next spring, causing new 

infections. Twig infections produce a “witches’ 

broom”. 

(Scirrhia) Needle Blight (Mycosphaerella pini 

(Dothistroma septospora)): Yellow spots on 

needles enlarge to form a red band. Needles 

die back from the tips above the band. Disease 

usually spreads from the base of the tree 

upward. Black, fungal fruiting bodies appear 

on needles, which are cast prematurely. 

Scleroderris Canker (Gremmeniella abietina): Does not 

occur in BC. Causes shoot blight and cankers 

on pines and Balsam fir in Eastern N. America. 




Fungicide applications are often 

ineffective, since spores can 

infect needles whenever the 

temperature is above freezing. 

Fungicides applied for 

Lophodermium needle cast (above) 

should also control Lophodermella. 

Apply fungicides at bud break 

and again about one month later. 

Fungicides have been shown to 

be generally ineffective for 

control of this disease. None are 

specifically registered. 

BRAVO Ultrex 90 SDG: 5.2 

kg/ha 


May cause needle spotting; apply 

under fast drying conditions. 

DACONIL 2787F: 9.5 L/ha 

DACONIL Ultrex: 5.75 kg/ha 

DACONIL 2787F: 2.4-4.8 L/ha 




Reduce water and 

nutritional stress, control 

weeds and space trees for 

good air circulation. 

Control weeds and space 

trees for good air 

circulation. 

Landscape Trees: 

Remove infected needles 

and rake up and destroy 

fallen ones. 


“witches’ brooms”. Rake 

up and burn, bury or 

compost old needles. 

Replace severely infected 

trees with resistant 

species. 

Do not plant near diseased 

trees. Remove lowest 

branches. Control weeds 

and space trees for good 

air circulation. 

Landscape trees: Remove 

infected needles, rake up 

fallen needles and burn, 

bury or compost. 

See Federal Plant 



Seedling Blight (Sirococcus conigenus): See under PICEA and General Disease Management: Sirococcus Blight, Chapter 9. 

Western Gall Rust (Endocronartium harknessii): No See General Disease Management: Western Gall Rust, Chapter 9. 

alternate host is required for this rust fungus. 

Rough, globular galls appear on branches or 

trunk several years after the infection occurred. 

Fungus is orange when fruiting. Infects hard 

pines (2- and 3-needled pines) such as lodgepole, 

mugho, Austrian, Scots and ponderosa. 

White Pine Blister Rust (Cronartium ribicola): This Chemical control is considered to be impractical on pines. 

rust attacks only 5-needled pines. Alternate 

hosts are currants and gooseberries. The rust Management: Do not grow 5-needled pines in Coastal BC, the 

attacks the living bark and cambium of white West Kootenays, or Northern Vancouver Island. Do not grow 

pine. First year symptoms of infection are currants or gooseberries in Interior BC where Ribes are 

blisters with secretions of pitch. In subsequent common. See General Disease Management: Rusts, Chapter 9. 

years, bright orange fungal spores appear in 

May on the rust cankers. Cankers eventually 

kill the infected branches. 



Insects: 

European Pine Shoot Moth (Rhyacionia buoliana): 

Insect presence is indicated from September to 

June by excess resin at buds and wilting shoots. 





See General Insect and Mite Management: European Pine Shoot 

Moth, Chapter 11. 

Pine Bark Aphid (Pineus strobi): This aphid feeds on the trunk and is recognized by a white cottony material in 

patches on the trunk. Several generations are produced during summer. See General Insects and Mite 

Management: Aphids and Adelgids, Chapter 11. 

Pine Needle Scale (Chionaspis pinifoliae): The scale is 

2.5 mm long, white with a yellow spot at one 

end. Needles may appear nearly white when 

heavily infested. 

Spray the crawler stage with one of the following 

insecticides in late May to early June: 

MALATHION 85E: 244.5 mL 

ORTHENE 75% SP: Mist blower = 1,312 g/1,000 L; Hydraulic 

sprayer = 637 g/1,000 L 


Dormant spray: 


Pine Sawflies (Neodiprion spp.): There are at least 4 CYGON 480-ORN, or LAGON 480E: 100 mL 

different species of sawflies that damage pines DURSBAN WSP: 44.8 g 

in BC. The larvae, which range in length from PRO DURSBAN TURF: 50 mL 

21-25 mm long, are voracious defoliators that SEVIN T&O: 230-350 mL 

can totally consume 1-year and older foliage. TRISTAR 70 WSP: 1 pack/1,000 L 

This gives the tree a bottle-brush appearance as 

the new growth develops. They overwinter as See General Insects and Mite Management: Sawflies, Chapter 11. 

eggs; larvae emerge in the spring. Mature larvae 

drop to the ground in mid-June to pupate. The 

emerging female adults lay eggs in slits along 

the margins of current season needles. 

Sequoia Pitch Moth (Synanthedon sequoiae) and 

Northern Pitch Twig Moth (Petrova 

albicapitana): Pitch moths damage both 

ornamental and native pines in BC. The 

sequoia pitch moth may attack any suitable 

host tree over 2 m in height, whereas the 

northern pitch twig moth is primarily a pest of 

saplings (= 0.3 to 3.0 m in height). The larvae of 

both species burrow into the main stem or 

branches. Damage is easily located by the large 

pitch masses produced at the entry points. 

Larval feeding can kill terminal shoots or 

produce weakened and crooked trunks. 

PLATANUS - SYCAMORE, PLANE TREE 

Diseases: 

Anthracnose (Apiognomonia veneta): This fungal 

disease overwinters in cankers on infected 

twigs and dead leaves. In early spring, young 

leaves are killed as they emerge from buds. 

Later infection causes brown blotches on either 

side of the mid-vein, and severe defoliation 

may result. Twigs and branches can be girdled 

and killed. It is most severe in warm, wet 

springs. 

There are no effective pesticide controls for pitch moths. 

Management Options: 

Protect trees from injury; pitch moths more frequently attack 

pines that have pruning wounds or other injuries than 

uninjured pines. 

Remove infested branches. Prune in the fall so the wounds 

begin to close before the egg-laying adults emerge in spring. 

Physically remove pitch masses and kill the enclosed larva or 

pupa. There will be a single larva/pupa per mass. Physical 

removal can reduce re-infestations and local populations. The 

insect will have emerged from masses that are 2 or more years 

old. Older masses are harder and darker in colour. 


DACONIL Ultrex:150 g 


80WP: 275-350 g 


Apply at bud break and repeat 

every 7–14 days during wet 

weather in the early part of the 

growing season. 

Rake fallen leaves and burn, 

bury or compost. Prune out 

diseased branches. 

Fungicide treatments are not 

necessary or beneficial on 

large landscape trees: see the 

Ministry’s Home and Garden 

Guide. Some varieties of 

Platanus including the 

London Plane are generally 

less susceptible. 



Sooty Mould: Black mould appears on leaves. It 

grows on honeydew produced by aphids, 

whiteflies, scales, mealy bugs and leafhoppers. 



POPULUS - POPLAR AND ASPEN (COTTONWOOD) 

Diseases: 

Leaf Blister (Taphrina spp.): Bright, yellow-brown 

blisters of various sizes occur on leaves after 

long periods of cool, wet weather. 

Leaf Spot (Marssonina populi, Septoria populicola and 

other spp.): Brown spots or blotches appear on 

leaves and small cankers form on green twigs. 

Early defoliation and reduced growth may 

occur especially during wet years when 

symptoms are severe. 

Rust (Melampsora spp.): Yellow, then brown leaf spots 

occur in late summer/fall. Leaves may drop 

early. Spores released from yellow pustules on 

leaves cause the disease to spread. Older 

pustules turn brown. Alternate hosts are Abies, 

Larix, Picea, Pinus, Pseudotsuga and Tsuga. 

Needles are infected in spring by spores from 

fallen poplar leaves. 

Shoot Blight (Venturia tremulae): Dark brown to black 

lesions form on succulent leaves and new 

shoots. Leaves wither and dying shoots form a 

“shepherd’s crook” at the tip. 

Insects: 

Poplar and Willow Borer (Cryptorhynchus lapathi): 

Larvae (grubs) attack limbs and trunks causing 

black, swollen scars. Old damage is indicated 

by death of small stems, 2-8 cm in diameter. 

Current damage is indicated by splits and holes 

in bark from which sap and sawdust exude. 

Affected limbs may break off. The adult weevil 

is greyish-brown with a wide cream-coloured 

band across the mid-section of the body. It is 1 

cm long and appears in mid-summer. 

Satin Moth (Leucoma salicis): Larvae are defoliators of 

poplars and willows. Adult moths are pure 

satin white. Caterpillars are black with red and 

white markings and grow up to 5 cm long. 

They appear in May and late July and 

skeletonize the foliage until fall. 



Control insects to reduce sooty mould. Successful insect 

control will prevent sooty mould. See the Ministry’s Home and 

Garden Guide for landscape tree recommendations. 



SENATOR 70WP: 110 g 

Early spring applications at 

budbreak may be justified if trees 

are small enough to spray. 

Control is not usually 

required. 

This disease rarely 

requires control on larger 

trees in the nursery or 

landscape. 

No fungicides are specifically registered for this disease. 

Application of fungicides for leaf spot (above) may help to 

control this disease if applied before the disease is 

widespread. 

Management: Collect fallen leaves and compost, burn, or 

bury. This disease is very common in late summer on native 

poplar and cottonwood. It usually does not damage trees, 

although it can be unsightly on landscape and nursery trees. 

More severe damage can occur on the alternate hosts if grown 

nearby. 

Fungicides applied for leaf spot 

(above) should also help to 

control shoot blight. Apply at 

bud-break if needed. 

The fungus can overwinter 

on diseased shoots and 

leaves. Prune out and 

destroy affected shoots. 


compost leaves in fall. 

Remove and burn badly 

infested trees and limbs. 

The boring grubs cannot 

be controlled. Insecticides 

are directed against adults 

and new, pre-boring 

grubs. See General Insect 

and Mite Management: Bark 

Beetles and Wood Borers, 

Chapter 11. 

AMBUSH 500EC: 7 mL 

BIOPROTEC CAF: 4 L/ha 

See General Insect and Mite Management: Caterpillars and Moths, 

Chapter 11. 







PRUNUS - FLOWERING CHERRY, PLUMS, etc. (For Commercial Orchards - 

See BCMA Tree Fruit Production Guide) 

Diseases: 

Bacterial Canker, Blight, Blast, Leaf Shot-Hole and 

Spot (Pseudomonas syringae pv. syringae): This 

bacterial disease is very damaging at the Coast 

in cool, wet springs. It causes cankers, 

exudation of gum and dieback of girdled 

branches. Gumming occurs at margins of 

cankers in spring, usually after a rain. Under 

wet conditions, numerous leaf spots are caused 

by rain-splashed bacteria. Spots often drop out 

leaving a “shot-hole”. Blossoms and new 

shoots may brown off completely giving a 

“blasted” appearance. New infections cease 

once weather turns warm. See General Disease 

Management: Bacterial Blight / Canker, Chapter 9. 

Brown Rot (Monilinia spp.): This fungal disease 

causes blossom blight and dieback of new 

shoots in late spring, followed by fruit rot in 

summer. Fruit turn brown during ripening, 

later becoming mummified. Dead blossoms 

and fruit exhibit a brown, fuzzy mould in wet 

weather. The fungus overwinters on 

mummified fruit and in small cankers on 

infected twigs and at the base of buds. The 

disease is most severe in warm, wet conditions. 

In Coastal areas, symptoms tend to overlap 

with those of bacterial canker (see above), 

although brown rot infection tends to occur at 

warmer temperatures. 

Cherry Leaf Curl or “Witches’ Broom” (Taphrina 

cerasi): Large, broom-like tufts develop on 

branches at blossom time. These branches have 

few flowers and leaf out earlier than other 

branches. The brooms do not bear fruit and 

they get larger each year. 

Cherry Leaf Spot (Blumeriella jaapii; anamorph 

Coccomyces): Brown to purple leaf spots; 

smaller on sour cherry than on sweet cherry. 

Large areas of leaves may be killed. Spots often 

drop out leaving a shot-holed appearance. 

Spots may also occur on fruit stems causing 

drop. White spore masses of the fungus appear 

within the spots. Common in the Interior but 

rarely occurs at the Coast. 


Apply prior to fall rains and 

again when the majority of 

leaves have fallen. 

Recommended to apply 

additional sprays immediately 

following pruning or grafting. 

Copper may cause leaf spot if 

applied under cool, cloudy 

conditions. To reduce injury, use 

the high rate for fall and delayed 

dormant applications and the 

low rate in the growing season. 

Obtain stock from sources 

believed to be free of 

disease. 

‘Royal Ann’, ‘Bing’, 

‘Lambert’ and ‘Van’ 

cherries are highly 

susceptible. Use Mazzard F- 

12-1 rootstock for cherries. 

Disinfect pruning tools 

between trees. Eliminate 

old, infected cherry trees 

from vicinity of fields 

where Prunus nursery stock 

is being grown. 

Apply at pink-bud stage. If wet weather occurs at this time, 

repeat sprays at 50% bloom and full bloom: 

BOTRAN: 1.75 kg/ha (peach) 

BRAVO 500: 5-9 L/ha 

CAPTAN 80-WP: 3.75-4.5 kg/ha 

FUNGINEX DC: 75 mL 

KUMULUS DF: 750 g 

ROVRAL WP & WDG: 1.5 kg/ha 

TOPAS 250E: 500 mL/ha 

Apply in all regular sprays except blossom: 

BORDEAUX: 200 g COPPER 53W + 400 g HYDRATED LIME 

Apply copper under fast drying conditions. 

Ornamentals only: DACONIL 2787F: 250 mL or DACONIL 

Ultrex: 150 g 

Remove mummified fruits from tree and ground during 

dormant season. Prune out cankered twigs. 

Refer to the Ministry’s Tree Fruit Production Guide for 

additional chemical control options. 

See Peach Leaf Curl, below. 

Prune out “witches’ 

broom” 30 cm below point 

of infection. Remove old, 

infected trees from the 

nursery. 

COPPER SPRAY 50: 200 g + HYDRATED LIME: 400 g 

EQUAL 65WP: 2.25 kg/ha 

FERBAM 76 WDG: 175-200 g 


TOPAS 250E: 500 mL/ha 

Make the first application at petal fall. In the 3 weeks prior to 

harvest make a 2nd and 3rd application at a 7-10 day interval. 



Coryneum Blight, Shot-hole (Wilsonomyces 

carpophilus; anamorph Stigmina carpophila): This 

fungal disease infects apricots, cherries and 

peaches. Twigs develop small dark circular 

spots. Some become gummy. Small reddishbrown 

to purple spots appear on leaves and 

then drop out, leaving a shot-holed 

appearance. Spots also appear on peach and 

apricot fruit. 

Crown Gall (Agrobacterium tumefaciens): This bacterial 

disease causes galls to form on roots and stems. 

The bacteria can remain in the soil in the 

absence of a host for several years. 

Cytospora Canker (Cytospora spp.; teleomorph 

Leucostoma species): This fungal disease is 

important on stone fruits, particularly on 

peaches in the South Okanagan and can also 

occur in Coastal BC. Slightly sunken cankers 

are formed on the bark. Black, pimple-like 

fruiting bodies, which extrude white tendrils of 

spores under wet conditions, can be seen in the 

cankers. The fungus also attacks apple and 

other ornamental trees and shrubs. Infection 

results from spores splashing on wounds 

caused by pruning, sunburn or breakage of 

branches. 

Little Cherry Disease/Little Cherry Virus: Infected 

black cherries have small pointed, pinkishcoloured 

fruits with insipid flavour. On sour 

cherries, fruits are small, yellowish or pink and 

the tree has loss of vigour. Flowering cherries, 

such as ‘Kwansen’ and ‘Shirofugen’, may be 

symptomless carriers of little cherry virus. The 

main vector is the apple mealy bug. 

Peach Leaf Curl (Taphrina deformans): This disease, 

which infects only peaches and nectarines, is 

most severe in wet areas. The fungus 

overwinters on bark and twigs. It infects buds 

during late winter as they are swelling. Leaves 

are yellow to reddish initially and become 

thickened and fleshy, later developing a dusty, 

white coating of spores. Infected leaves fall 

prematurely and new, healthy leaves may 

appear later in the summer. 





COPPER 53W: 400 g 

Prune out diseased twigs 

COPPER SPRAY 50: 600 g during the dormant season. 

Apply before fall rains and 

again when the majority of 

leaves have fallen. Copper may 

cause leaf spotting under cool, 

cloudy conditions. 


ZIRAM 85W: 8 kg/ha 

Avoid planting susceptible species in beds known to be 

infested. Remove all galls when moving stock. Disinfect all 

tools and work areas with a strong bactericide when working 

with gall-infected material. Inspect roots and do not plant 

gall-infected material. See General Disease Management: Crown 

Gall, Chapter 9. 

Apply at leaf drop or in early 

spring before bud break: 

BRAVO 500: 5-7 L/ha 



Repeat before bud break in 

spring unless another dormant 

spray has been used. 

Apply by the end of January: 

FERBAM 76 WDG: 175-350 g 

Dormant: 

LIME SULPHUR: 10 L 

Verticillium Wilt (Verticillium spp.): See General Disease Management: Verticillium Wilt, Chapter 9. 

Minimize wounding 

especially during wet 

weather. Prune as late as 

possible in the dormant 

season. It is important to 

remove all cankered wood 

from the vicinity of the 

nursery or orchard. 

Whitening of the bark to 

prevent sunscald is also a 

useful preventive measure. 

Avoid excessive nitrogen or 

irrigation in the growing 

season. 

Use virus-tested stock for 

propagation of both sweet 

and flowering cherries. 

Refer to Little Cherry Control 

Regulations, Chapter 2, for 

restrictions on movement 

and production of cherries 

in the Little Cherry Control 

Areas of BC. 

Where practical, pick and 

destroy infected leaves 

before sporulation occurs in 

early summer. 

Fall sprays will also control 

Coryneum blight. 






PRUNUS LAUROCERASUS - CHERRY LAUREL 

Diseases: 

Leaf Spots, Shot-hole - Bacterial (Pseudomonas 

syringae pv. syringae), Fungal (Cercospora spp. 

and other fungi): The bacterium, Pseudomonas 

syringae, and several fungi can cause reddishbrown 

leaf spots that may fall out giving the 

leaf a shot-holed appearance. Identification of 

the causal agent is often difficult, but may be 

necessary for selection of the proper chemical 

control. Fungal diseases are more common in 

the Interior and bacterial blight at the Coast. 

Insects: 

Cherry Bark Tortrix (Enarmonia formosana): The 

larvae live under the bark and show a 

preference for scar tissue from graft unions. 

Frass (excrement) and gum-like resin can be 

observed at the entrance of the tunnels. The 

larvae overwinter and pupate in the spring 

inside the tunnels. Moths have dark brown 

forewings with yellow-orange lines. They 

emerge in May and periodically through the 

summer. 

Cherry Ermine Moth: See MALUS: Apple Ermine Moth. 

Leafrollers: Larvae are green with black heads. They 

feed on leaves and fruit, and drop on silk 

threads when disturbed. 

Peach Tree Borer (Synanthedon excitiosa): It affects 

apricots, cherries, chokecherries, nectarines, 

peaches, plums and prunes. Females lay eggs 

near the soil line on tree trunks where, after 

hatching, the larvae tunnel under the bark. 

Larvae are cream colored with brown heads 

and reach up to 30 mm long. Adults are clearwinged 

moths around 25 mm long with yellow 

banded abdomens. Can girdle and kill young 

trees. Older trees are weakened and become 

susceptible to other pests. 

Pear Sawfly (Caliroa cerasi): Adult is a shiny black fly 

with four wings. Black slug-like larvae 

skeletonize leaves in summer. 

Apply fungicide or bactericide 

to protect new growth in 

spring. 

Fungal: 




Bacterial Blight / Canker, Chapter 

9. 

Because of the long flight 

period of the moths and the 

bark-boring habit of the larvae, 

effective chemical controls have 

not been developed. 


Avoid overhead irrigation 

in the afternoon or evening. 

Destroy fallen leaves. Very 

susceptible varieties such as 

‘Zabeliana’ cannot be 

grown disease-free in 

containers under sprinkler 

irrigation. They can be more 

successfully grown in the 

field. They must not be 

subjected to daily 

sprinkling in the landscape 

and they should not be 

planted under any type of 

cherry tree. 

Older infested trees should 

be cut down to reduce 

breeding of this insect. 

DIAZINON 50WSP or 50EC (cherries): 100 g or 100 mL 

DIPEL WP: 2.25-3.35 kg/ha 

DIPEL 2X DF: 1.125-1.675 kg/ha 

DOKTOR DOOM: 60-480 mL/0.4 ha 



sprayer = 637 g/1,000 L 


Spray when bearing trees are in pink-bud stage. 

DECIS 5 EC: 6.8 mL 

ISOMATE-P PHEROMONE: 

250 to 625 dispensers/ha for 

peaches, nectarines and 

apricots. One dispenser per 

tree. Apply in the spring prior 

to moth emergence, one 

application can provide seasonlong 

control. 

MILLENIUM: 1 tray/9.4 L 



Management: Sawflies, Chapter 

11. 

Install a metal cone-shaped 

collar around the base of 

the tree before eggs are laid 

to prevent larvae from 

boring into the base of the 

tree. Kill larvae in tunnels 

by probing with a wire or 

by opening the tunnels to 

find and destroy them. 

Apply when damage is first 

noticed in spring and again 

in July-August. 



PSEUDOTSUGA - DOUGLAS FIR 

Diseases: 

Diaporthe Canker (Diaporthe lokoyae; anamorph 

Phomopsis lokoyae): This fungus infects new 

shoots. The sunken cankers are elliptical and 

differ in size. Larger cankers can be up to 75 cm 

long. They develop during the dormant season. 

Dieback occurs when a limb is girdled. Tiny, 

black fruiting bodies (pycnidia) are found in 

the cankered area. 

Douglas Fir - Cottonwood Rust (Melampsora 

occidentalis): Yellow rust pustules are present 

on underside of needles, which turn yellow 

and die prematurely. Cottonwood leaves 

develop angular, yellow spots on the upper leaf 

surface that correspond to yellow and brown 

rust pustules on the lower surface. 

Grey Mould/Seedling Blight (Botrytis cinerea): 

Individual new shoots wilt and turn brown 

early in the growing season, causing 

conspicuous blight in unusually wet springs. 

Needle Cast (Rhabdocline pseudotsugae): Yellow spots 

appear on current season needles in early fall. 

Spots enlarge the following spring and turn 

into purplish-brown bands in May or June. 

Spores shed from these bands infect newlyopening 

needles in spring. The old needles fall 

off leaving a single year’s needles on the tree. 

Cool, wet weather promotes infection. 

Needle Cast (Rhizosphaera kalkhoffi): Small yellow to 

greyish-green, mottled spots appear on current 

year’s needles in late summer, particularly on 

lower branches. Spots then turn purplishbrown. 

See PICEA: Needle Cast for a full 

description of this disease. 




Fungicides applied to control 

other diseases listed below will 

also help to prevent infection 

by this fungus. 


Keep trees healthy. Prune out 

infected limbs well below the 

canker. Remove prunings 

from the area and burn, bury 

or chip, since spores from 

dead, cankered limbs can 

cause new infections. 

Both hosts are required for 

survival of the rust. 

Susceptible cottonwoods 

include Populus trichocarpa, 

P. balsamifera and hybrid 

poplars. These should be 

removed from the 

perimeter of fields 

producing Douglas fir. See 

also POPULUS: Rust. 

See General Disease Management: Botrytis Blight and Storage 

Moulds, Chapter 9. 



DACONIL 2787F: 2.4–4.8 L/ha 




Treat when new growth is 1-5 cm in length. Repeat sprays 

every 10-14 days in cool, wet springs. 

BANNER MAXX: 35 mL (for use 

on Christmas trees only) 


Rhabdocline Needle Cast (see 

above) will help to control this 

disease also. 

Seedling Blight (Sirococcus conigenus): See under PICEA and in General Disease Management: Sirococcus Blight, Chapter 

9. 

Swiss Needle Cast (Phaeocryptopus gaeumannii): 

Fungal fruiting bodies appear as rows of black, 

pinhead-like dots on the underside of needles. 

There may be defoliation of one- and two-yearold 

needles in early spring. 

Insects: 

Cooley Spruce Gall Adelgid (Adelges cooleyi): Insects 

attack both spruce and Douglas fir. On Douglas 

fir they are present as woolly aphids in spring. 

See under PICEA-SPRUCE. 


Rhabdocline Needle Cast (see 

above) will help to control this 

disease also. 

See General Insect and Mite Management: Aphids and Adelgids, 

Chapter 9. 



Douglas Fir Needle Midge (Contarinia sp.): The adult 

is a small midge that emerges when buds are 

breaking. The fly lives for a few days; just 

enough time to mate and lay eggs. They 

deposit eggs in groups on expanding buds and 

new needles. The eggs hatch in a few days. The 

larvae penetrate and mine needles, and drop to 

the ground in the fall to overwinter. Even light 

infestations lower market value and 

appearance of Christmas trees. Moderate or 

heavy infestations cause serious defoliation. 

Infested needles become yellowed and angle 

sharply. 

Silverspotted Tiger Moth (Douglas Fir Webworm - 

Halisidota argentata): Newly-hatched larvae are 

greenish-brown, fuzzy and about 6 mm long. 

Later stages are up to 37 mm long, thickly 

haired and tufted with reddish-brown, yellow 

and black hairs. Larvae spin a tent or web 

around a branch and feed in or around the tent. 

PYRACANTHA - FIRETHORN 

Diseases: 

Fire Blight (Erwinia amylovora): New shoots wilt 

suddenly in spring, turning black/brown. The 

dead leaves hang down on infected twigs. It is 

uncommon in Coastal areas, but can occur 

during summer propagation in polyhouses. 

Scab (Venturia pyracanthae): Black scabs or blotches 

appear on leaves and berries. 




DIPEL WP: 62.5 g 

Apply when larvae first appear 

in March and tent is still small. 

Repeat spray in two weeks if 

necessary. 


Christmas tree growers 

should use emergence 

cages placed on the 

ground to determine 

midge emergence. 

Treatments should be 

applied when the buds are 

stretching. 


tents when seen in fall or 

spring. 

See General Disease Management: Fire Blight, Chapter 9 and 

COTONEASTER: Fire Blight. 


DACONIL 2787F: 250 mL or DACONIL Ultrex: 150 g 

Spray when blossoms open and at 10-day intervals at least 

twice more during early part of growing season. 

Destroy all fallen leaves if practical. Appendix D contains a 

list of resistant varieties. 

PYRUS – PEAR (For Commercial Orchards - See BCMA Tree Fruit Production Guide) 

Diseases: 

Anthracnose Canker (Cryptosporiopsis curvispora): See under MALUS. 

European Canker (Nectria galligena): See under MALUS. 


suddenly in spring, turning black/brown. The 

dead leaves hang downward on affected twigs. 

This bacterial disease is not considered to be a 

problem in Coastal areas. In the Interior, it can 

spread quickly at temperatures above 18°C in 

wet weather, especially following hail damage. 

Symptoms can be confused with Pseudomonas 

blossom blast, which is more common on the 

Coast and occurs earlier in the spring. 


Management: Fire Blight, 

Chapter 9. 

Prune out diseased branches 

at least 15 cm below the 

affected area in dormant 

season, or at least 30 cm 

below the affected area in the 

early growing season. ‘Bosc’ 

is highly susceptible and 

whole branches may need to 

be removed. 



Pear Trellis Rust (Gymnosporangium fuscum): Orangered 

spots with black centres appear on leaves in 

June-July. By late August, the spots thicken and 

spores emerge in spiky tufts from the lower leaf 

surface. Fruit and twig infections may occur on 

trees with large numbers of leaf infections. Juniper 

is the alternate host. Spores from juniper must reinfect 

pears each year, although in some cases 

repeating infections can occur from twig cankers. 

The disease is common in the Lower Mainland, 

but not in the Interior. A Domestic Movement 

Certificate is needed to transport pear nursery 

stock out of the Lower Mainland. See British 

Columbia Plant Protection Regulations, Chapter 2. 

Scab (Venturia pirina): See under MALUS. 


Pear Leaf Blister Mite and Pear Rust Mite (Eriophyes 

pyri and Epitrimerus pyri): Almost microscopic, 

white, worm-like mites produce blistering and 

russeting on leaves and fruit. The mite is within 

the blisters and is difficult to control during the 

growing season. Best control is achieved with a 

dormant spray. 

Pear Psylla (Psylla pyricola): Adults are green to 

brown and overwinter on the trees or on the 

ground and become active in March. Eggs are 

laid in spring before buds open during 

blossoming. Nymphs invade buds and feed on 

developing leaves and flowers. Later they 

move to leaves and live in honeydew drops. 

Summer eggs are laid on leaves. Three to five 

generations occur per season. Leaves blacken 

with sooty mould and fall off. 

Not known to be a pest in Coastal nurseries. 

More common in Interior orchards. 

Pear Sawfly (Caliroa cerasi): Adult is a shiny, black fly 

with four wings. Black slug-like larvae 

skeletonize leaves in summer. 





Repeat at 14-day intervals. No 

more than 6 applications per 

year. 

CAPTAN 80 WDG: 120 g; do 

not use Captan on ‘Anjou’. 

EQUAL 65W: 3.25 kg/ha; do 

not use in the Interior where 

resistance is common. 

FERBAM 76 WDG: 200 g 


KUMULUS DF: 400-750 g 

LIME SULPHUR: 125 mL 

MAESTRO 80DF: 3.75 kg/ha; 

do not use on ‘Anjou’. 

SULPHUR: See labels. 


Do not plant ornamental 

pears as landscape trees in 

the Lower Mainland. Avoid 

planting pear trees within 30 

m of susceptible junipers. 

Pick off infected pear leaves 

as you see them. The leaves 

and fungus will die quickly if 

removed in mid-summer. 

In addition to the control 

measures used for apple scab, 

pear scab control also 

requires measures to reduce 

overwintering on twigs. 

Prune out severely infected 

twigs during dormant season. 

Apply dormant or delayeddormant 

lime sulphur. 

European canker can infect 

through scab lesions on 

twigs. 

See General Insect and Mite Management: Mites, Chapter 11. 

AGRI-MEK 1.9% EC: 20-40 mL + 0.25% PARAFFINIC SPRAY OIL 

DIAZINON 50WSP: 150 g + 1 L of HORTICULTURAL OIL 

DYNO-MITE or SANMITE: 28.4 g 



LANDSCAPE OIL: 3 L 

LIME SULPHUR 23%: 10 L 

ACTARA 25 WG: 315-385 g/ha 

AGRI-MEK 1.9% EC: 20-40 mL + 0.25% PARAFFINIC SPRAY OIL 

DECIS 5 EC: 6.8-11.8 mL 

DIAZINON 50EC or 50WSP: 100 mL or 100 g 


INSECTICIDAL SOAP 47% or 50.5%: 2 L 

MALATHION 500 E: 125-250 mL 

POUNCE 384 EC: 17.5-35 mL. Use the low rate to control 

overwintering adults prior to bloom. 




LANDSCAPE OIL: 2 L 


Treat when damage is first noticed in spring and again in July- 

August. See General Insect and Mite Management: Sawflies, 

Chapter 11. 



QUERCUS - OAK 

Diseases: 

Anthracnose (Apiognomonia sp. (Discula quercina)): 

This disease is very similar to anthracnose of 

Platanus. It is most damaging on white oak. 

Spots on leaves run together to form blotches 

along veins. Rain favours infection. Defoliation 

can occur. The disease is often worse on trees 

under stress and in years with warm, wet 

springs. 

Insects: 

Bruce Spanworm (Operophtera bruceata) and Winter 

Moth (Operophtera brumata): These loopers 

defoliate trees during May and early June. 

Jumping Gall Wasp (Neuroterus saltatorius): This 

wasp causes small, 1-1.5 mm, yellow galls on 

leaves of Garry oak. Galls are visible from June 

to September, accompanied by severe and 

chronic mid-summer leaf scorching. The wasp 

is known to occur only on Saltspring and 

southeast Vancouver Island. 

Oak Leaf Phylloxera (Phylloxera glabra; Phylloxera sp.): 

This small, yellow to orange, aphid-like insect 

is present throughout southern BC. It causes 

mid-summer leaf spotting, scorching and 

defoliation of Garry oak in landscape and 

nurseries. Trees may eventually die. Other 

ornamental oaks are also attacked but are not 

as severely affected. 

Oak Leaf Shredder (Croesia semipurpurana): Larval 

feeding produces numerous tiny holes in 

young foliage. The larvae then tie leaves 

together with silk webbing. Larvae pupate in 

the soil; adults emerge in summer and deposit 

eggs in bark of 2- and 3-year-old twigs. Several 

years of severe defoliation can kill a tree. 

RHAMUS - BUCKTHORN 

Diseases: 

Rot of Stem Cuttings (Pythium/Phytophthora spp.): 

Basal rot of stem cuttings and poor rooting. 







80WP: 275-350 g 


Apply when buds begin to swell. 

Repeat sprays at 7-14 day 

intervals in wet springs. 


On small nursery trees, a 

fungicide spray program 

is recommended during 

the spring to prevent 

infection. Large trees can 

sustain severe disease in 

some years without 

permanent damage and 

spraying is usually 

impractical. See under 

PLATANUS. 

See General Insect and Mite Management: Bruce Spanworm and 

Winter Moth, Chapter 11. 

Nurseries: 

Apply a general systemic 

insecticide in mid-May. Contact 

the BCMA entomologist for 

specific recommendations. 

Landscape: 

No practical chemical control. 

ORTHENE 75% SP: Mist blower 

= 1,312 g/1,000 L; Hydraulic 

sprayer = 637 g/1,000 L 

RHODODENDRON and AZALEA (see AZALEA) 

RHUS - SUMAC 

Insects: 

Pear Leaf Blister Mite (Eriophyes pyri): Almost 

microscopic white worm-like mites produce 

blistering and russeting on leaves. 

Several naturallyoccurring 

predators and 

parasitic insects feed on 

the gall wasp. 

For nurseries, see General 

Insect and Mite 

Management: Aphids, 

Chapter 11. It is not 

usually practical to treat 

large landscape trees. 

Rogue out trees showing 

severe symptoms in new 

plantations. 


Cuttings, Chapter 9. 



Chapter 11. 



ROBINIA 

Diseases: 

Fusarium Canker (Fusarium spp.): Several Fusarium 

species can cause cankers and wilting 

symptoms on locust. 

ROSA – ROSE 

Diseases: 


Dark brown, sunken spots appear on leaf and 

flower stalks and calyx parts. Flower buds die 

without opening. Black streaks appear on oneyear-old 

stems. The disease commonly occurs 

during cool, wet weather in spring. 

Black Spot (Diplocarpon rosae): Black to reddishbrown 

spots with smooth or irregular, 

“fringed” edges are visible on both sides of the 

leaf. Leaves yellow and drop. Spots can 

resemble those caused by downy mildew (see 

below). 

Brand Canker (Coniothyrium spp.): This fungal 

disease causes small, longitudinal splits in the 

bark, through which tiny, black, fungal fruiting 

bodies protrude. It often affects plants that are 

under stress or damaged by other factors. 

Brown Canker (Cryptosporella spp.): This canker has a 

light brown centre with a purple margin. 

Yellow to brown spores exude from the canker 

in damp weather. 

Crown Canker (Cylindrocladium scoparium): This 

disease is primarily a greenhouse problem. It 

has rarely been found in BC: once on imported 

bareroot stock from the Southern US, where the 

disease occurs in fields. The bark is blackened 

and water-soaked at the graft union. Canes 

become girdled and produce few and inferior 

blooms. 

Crown Gall (Agrobacterium tumefaciens): Galls appear 

on lower stems and roots. 




COPPER SPRAY 50: 600 g; apply 

once in October and again in 

January. 


CAPTAN 50-WP: 200-250 g 

CAPTAN 80-WP: 125-150 g 

CAPTAN 80 WDG: 120-140 g 

COMPASS 50WG: 15-20 g 




EAGLE WSP T&O: 30 g 

FUNGINEX DC: 100 mL 


PHYTON 27: 390 mL 

RHAPSODY: 1-2 L 


PHYTON 27: 125-400 mL 

(miniature roses) 


Cut out and burn or bury 

infected plant parts. 



Blight / Canker, Chapter 9. 

Remove infected leaves. 

Water during the day so that 

leaves dry off before sunset. 

Rake up and compost fallen 

leaves and apply lime 

sulphur during dormant 

season. Protect young leaves 

on susceptible varieties before 

infection with the other 

fungicides listed. For resistant 

varieties see Appendix J. For 

landscape and home garden 

control see the Ministry’s 

Home & Garden Pest 

Management Guide for British 

Columbia. 

Prune out diseased canes in 

early spring. Disinfect 

pruning tools between 

bushes. Avoid leaving large 

pruning stubs. 

Same as for Brand Canker 

(see above). 

Plant new stock in a sterile 

growing medium. Do not 

import stock from areas 

where the disease is known to 

occur in production fields. 

The fungus is soil-borne once 

it is introduced. 

See General Disease Management: Crown Gall, Chapter 9. 



Downy Mildew (Peronospora sparsa): Infection by 

wind-blown sporangia produced by the 

organism cause reddish-purple leaf spots to 

appear on the upper leaf surface during cool, 

wet weather. Infected leaves yellow and drop, 

leading to poor plant vigour and growth. 

Disease symptoms resemble those caused by 

crown gall, nutritional or environmental factors 

and even black spot. The fungus can be 

systemic in infected plants, which may not 

show symptoms in the greenhouse, so is often a 

problem in propagation nurseries. 

Powdery Mildew (Sphaerotheca spp.): A white, 

powdery growth appears on leaves. Young 

leaves curl and are more purplish than normal. 

Rose Graft Canker (Coniothyrium rosarum): Cankers 

develop in forcing beds at the graft union. 

Canes die when the canker has encircled the 

graft. 

Rust (Phragmidium spp.): Rusty yellow and brown 

spots appear on leaves and stems. 

Stem Canker (Leptosphaeria spp.): Black spots and 

stem cankers form, often at tips where canes 

have been pruned back. 

Viruses: 

Mosaic: Chlorotic areas appear along midribs of 

leaflets and leaves may be distorted. Infected 

plants may do well until stressed, then can 

quickly drop leaves and decline. 

Streak: The streak virus causes brown rings and 

brown vein-banding on fully expanded leaves 

and brownish or greenish rings on canes. 

Transmitted by grafting. 

Insects: 

Rose Midge (Dasineura rhodophaga): Larval (maggot) 

feeding occurs within the emerging leaf and 

flower buds, which causes the buds to wither 

and turn black. Midge feeding can cause 

complete failure of a bloom cycle. Peak injury 

occurs from mid-June to early July, and in late 

August/September. 

Sawfly (Rose Slug) (Endelomyi aethiops): The larval 

stage of the rose slug feeds only on roses. It 

skeletonizes the upper surface of leaves. The 

larva has a brown head and pale-green body 

that is up to 13 mm long. It moves to the soil in 

mid-summer to overwinter and pupate the 

following spring. There is only one generation 

per year. 






Management: 

In the polyhouse, monitor plants and remove infected leaves; 

control humidity; clean up crop debris at the end of the season; 

alternate crops if possible. 

In the nursery, avoid overhead watering in the evening. 

Some of the most popular roses, including ‘Austin’, 

‘Meidiland’ and mini-roses are highly susceptible. Climbing 

roses are often infected but tolerant of the disease, which 

produces only mild leaf spotting. However, they are a source 

of infection for other roses in the nursery and landscape. 


For resistant varieties see Appendix J. 


Management: Rust, Chapter 9. 

Use disease-free wood for 

grafting. Rogue out diseased 

plants. 

Remove all infected 

overwintering leaves. For 

resistant varieties see 

Appendix J. 

See Brand Canker (above). 

Sterilize pruning tools. 

Provide good growing 

conditions. 

Use virus-free rootstocks and scionwood for propagation. 

Many roses will sustain some mosaic virus infection without 

serious injury, unless grown under stressful conditions. Water 

and fertilize to promote healthy, vigorous plants. 

Use virus-free rootstocks and 

scionwood for propagation. 

ORTHENE 75% SP: Mist 

blower = 1,312 g/1,000 L; 

Hydraulic sprayer = 637 

g/1,000 L 

See General Insect and Mite Management: Sawflies, Chapter 11. 

Thrips: Elongate, very small insects. Cause bronzing and drying of leaves and petals. Buds turn black and fail to open. 

See General Insect and Mite Management: Thrips, Chapter 11. 



SALIX - WILLOW 

Diseases: 

Blight (Marssonina salicicola, Septoria spp. and other 

fungi): These fungi overwinter as twig cankers. 

During wet spring weather, new leaves and 

shoots become infected. Under severe 

conditions, defoliation and extensive twig 

death occurs. 

Insects: 

Alder Flea Beetle (Altica ambiens ulni): The beetle is 6 

mm long, metallic green to blue with yellow 

legs. The adult and larval stages skeletonize 

leaves, but seldom cause serious injury. 

Aphids: A small to medium-sized, light green or 

yellow aphid sucks sap from leaves. A large, 

black aphid feeds on the bark of twigs. Large 

numbers produce much honeydew and attract 

wasps. 

Poplar and Willow Borer (Cryptorhynchus lapathi): 

The adult beetle is 6 mm long, dark brown, 

mottled, with light brown, grey, and pink 

scales. Larvae feed in soft tissue of inner bark 

and sapwood, especially at the base of the tree, 

which they kill. 

Satin Moth (Leucoma salicis): The larvae are 

defoliators of cottonwood, poplar and willow, 

and occasionally attack oak and aspen. 

SKIMMIA 

Diseases: 

Black Root Rot (Thielaviopsis basicola): T. basicola is a 

soil-inhabiting fungus that causes root rot on a 

broad range of ornamental plants. The disease 

is favoured by wet and warm (12-18 o C) soils. 

The symptoms include yellowing of foliage, 

branch dieback, and blackened areas on roots. 

SORBUS - MOUNTAIN ASH 

Diseases: 

Apple Scab (Venturia inaequalis): This fungus causes 

scab (black spots) on leaves and fruit. Leaves 

are curled and distorted. New infections occur 

whenever there is a moderate to prolonged 

rainy period. The same fungus causes apple 

scab. 


suddenly in late spring and turn black or 

brown. Dead leaves hang downward on 

infected twigs. It is not considered to be a 

problem in Coastal areas. 




No fungicides are registered 

for control of these diseases 

on willow. 


In nurseries, prune and burn 

diseased twigs at least twice 

per year. See under 

POPULUS. 

See General Insect and Mite Management: Aphids, Chapter 11. 

DURSBAN WSP: 44.8 g See under POPULUS and in 

PRO DURSBAN TURF: 50 mL General Insect and Mite 

Management: Bark Beetles and 

Wood Borers, Chapter 11. 

See under POPULUS and in General Insect and Mite 

Management: Caterpillars and Moths, Chapter 11. 



leaves. Control scab on apples 

if grown nearby (see under 

MALUS). 




Mites: 

Pearleaf Blister Mite (Phytoptus pyri): The mite is a 

tiny, elongated, worm-like pest, about 0.2 mm 

long. They overwinter beneath outer bud 

scales. Eggs are deposited in spring in leaf galls 

that develop as a result of feeding and 

irritation. Small, brown blisters appear on 

lower surfaces of leaves in spring. 

SYRINGA - LILAC 

Diseases: 


Dark black streaks appear on young shoots or 

on one side of a shoot in early spring. Leaf 

spots are brown, often with a yellow halo. 

Flowers wilt and turn brown. Buds are 

blackened. Rainy springs favour disease. 

Powdery Mildew (Microsphaera spp.): A white, 

powdery growth appears on leaves usually late 

in the growing season. 

Insects: 

Ash and Lilac Borer (Podosesia syringae): See under FRAXINUS - ASH 

Leafminer (Caloptilia syringella): The adult is a small, 

slender grey moth. It begins the season as a 

leafminer in late May, just before blossom time. 

The mines may run together to form a blotch. 

The larva forms a cocoon within the fold of a 

leaf where it overwinters. 

Oyster Shell Scale (Lepidosaphes ulmi): This is the 

most common scale attacking lilac. It is 

identified by its oyster-like appearance. 

TAXUS - YEW 

Diseases: 

Root Rot (Phytophthora sp.) 

THUJA - RED CEDAR, ARBORVITAE 

Diseases: 

Armillaria Root Rot (Armillaria spp.): Branches turn 

brown, often starting on one side of the tree. 

Examination reveals root rot and decay at the 

base of the trunk. 

See General Disease Management: Root Rot Caused 

by Armillaria, Chapter 9. 






See General Disease Management: Bacterial Blight/Canker, 

Chapter 9. 


See General Insect and Mite Management: Leafminers / Needle 



See General Disease Management: Root Rots Caused by 

Phytophthora and Pythium, Chapter 9. 

No chemical control. 

Management: Avoid growing Thuja in soils recently cleared 

of native forest vegetation. Rogue out and burn diseased 

plants taking care to remove all traces of tree roots and fungal 

“rhizomorphs” before re-planting with resistant species. For a 

list of resistant plants see Appendix M. 



Berckmann’s Blight / Seiridium Blight / Coryneum 

Canker (Seiridium spp., teleomorph Coryneum 

berckmannii): Severe twig and branch canker 

occurs only on Platycladus orientalis (formerly 

Thuja orientalis). Foliar blight can also occur on 

Thuja plicata and Chamaecyparis spp. Foliage 

looks greyish and infected twigs dieback. 

Young twig tips are infected, and the disease 

progresses inward on the tree. Spores infect 

twigs in late September but disease symptoms 

may not be apparent until the following spring. 

Tiny, black, fungal fruiting bodies are found in 

late summer/fall where twigs and branches are 

girdled. 

Cedar Flagging (physiological): Common on Thuja 

plicata (western red cedar). In late summer, 

patches of foliage turn yellow to reddish-brown 

on branches scattered about the tree. 

Foliar Blight/Dieback (Kabatina thujae): This disease 

affects Thuja occidentalis and Chamaecyparis spp., 

causing leaf and shoot dieback in spring. It is a 

sign that the plants are not growing well. 

Keithia Blight (Didymascella thujina): Tiny, circular, 

brown to black, fungal fruiting bodies appear 

on scale leaves in late spring. The leaves then 

turn brown and affected areas fall out. Later, 

infected leaves drop, leaving branches with a 

sparse or bare appearance. Dormant spores 

adhering to the foliage in the fall can germinate 

and cause new infections during propagation. 

Leaf Browning/Purpling (Environmental): Foliage 

takes on an overall brownish or purplish colour 

in early spring. This colour change may occur 

rapidly. Healthy plants will green-up as the 

growing season progresses. 

Note: During flowering, some varieties may 

exhibit an overall reddish-purple colour. The 

colour may become suddenly more noticeable 

in years with more intense flowering. 


Cypress Tip Moth (Leafminer) (Argyresthia 

cupressella): Adult moths are silvery-tan in 

colour and are active in early June. Eggs are 

inserted into the green tips of one and twoyear-old 

twigs. The larvae tunnel into leaf 

scales and remain there until the next spring. 

Infested twigs turn yellow, then brown in late 

winter. A cocoon is spun around the foliage in 

early June of the second year for the pupal 

stage. Two to three weeks later, adults emerge. 

Mites: Damage usually occurs first at the bottom of 

the plant and on the south side. Monitor by 

gently shaking the foliage above a sheet of 

white paper. 






80WP: 275-350 g 


Spray twice every fall and 

again in spring to protect new 

foliage. 


Apply once in the fall and 

every 2-3 weeks in the spring 

to protect new growth. 

Treat at least 3 times between 

March and mid-June. 


Management: Keithia Blight, 

Chapter 9. 


In late April, mid-June and 

early July, spray to control 

larvae outside the foliage or 

moths before egg laying. 


Prune out affected branches 

and twigs. This disease is the 

main limiting factor to the 

successful growing of P. 

orientalis in Coastal BC. 

Dying twigs are often 

infected by secondary fungi 

so a laboratory diagnosis is 

often needed to confirm this 

disease. 

A natural occurrence; not 

damaging to the tree. May be 

more severe in droughty 

years. 

Examine soil for correct pH, 

nutrient levels and drainage. 


Irrigate early in the day. 

Avoid overhead watering of 

Thuja plicata. T. plicata 

‘Atrovirens’ and ‘Excelsa’ are 

especially susceptible. Locate 

nursery beds of these varieties 

away from mature T. plicata 

windbreaks. Do not propagate 

from infected plants. 

Cold temperatures in winter 

and early spring, rather than 

drought, are responsible for 

the temporary leaf browning. 

Provision for shelter or 

windbreaks may help. T. 

occidentalis ‘Smaragd’ is less 

susceptible than other 

varieties. 




Redwood Bark Beetle (Phloeosinus sequoiae): The 

beetle commonly attacks weakened, dying or 

dead trees. The female beetle will bore into the 

inner bark and lay about 50 eggs. The emerged 

larvae feed in the sapwood and phloem. It 

overwinters as an adult or larva. Adults emerge 

in the summer and feed on small branches of 

cedar and cypress, which can lead to flagging. 

Root Weevils: Adults may girdle twigs a few 

centimeters from tips. Tips turn brown making 

the tree unmarketable. Serious damage may 

occur on landscape plantings also. 

TILIA – LINDEN 

Diseases: 

Sooty Mould: Black mould grows on aphid secretions 

on leaves. 

Mites: 

Gall Mite (Phytoptus tiliae): Mites form red to 

greenish, pocket-like galls on the upper surface 

of leaves. Galls are about 5 mm long. This is a 

pest of T. cordata. 

TSUGA - HEMLOCK 

Diseases: 

Botrytis Blight (Botrytis cinerea): Botrytis causes a 

foliar blight of seedlings and container-grown 

plants in humid conditions. 

Tip Blight (Sirococcus conigenus): Death of young 

shoots, often forming a “hook” at the tip. Also 

causes seed decay and seedling blight. See 

under PICEA. 

Insects: 

Hemlock Woolly Adelgid (Adelges tsugae): This 

sucking insect appears as white, cottony puffs 

on the bark and base of needles. Infestation 

often leads to the production of abundant 

black, sooty mould. Premature needle drop 

may occur. 

See Comment 30 in Federal Plant Quarantine 

Regulations in Chapter 2. 

Hemlock Looper (Lambdina fiscellaria): Pale yellow 

caterpillars, up to 25 mm long, with a double 

row of small black dots along body, cause 

severe defoliation of outer shoots and twigs. 





See General Insect and Mite Management: Bark Beetles and Wood 

Borers, Chapter 11. 

See General Insect and Mite Management: Root Weevils, Chapter 

11. 

Control aphids to reduce sooty mould. See General Insect and 

Mite Management: Aphids and Adelgids, Chapter 11. 

Dormant season only: 

DORMANT OIL: 2 L 

See General Disease Management: Botrytis Blight and Storage 

Moulds, Chapter 9. 

See General Disease Management: Sirococcus Blight, Chapter 9. 


50.5%: 2 L; spray after May 1 

LANDSCAPE OIL: 1-2 L to 

control eggs, nymphs and 

adults 


Management: Woolly Adelgids, 

Chapter 11. 

FORAY 48BA: 2.4-3.2 L/ha 

THURICIDE 48LV: 160-240 

mL 

Nitrogen fertilization has 

been shown to enhance 

adelgid survival and negate 

pest control measures. If this 

insect is a problem, reduce 

nitrogen fertilization as much 

as possible. 






ULMUS - ELM 

Diseases: 

Dutch Elm Disease (Ceratocystis ulmi ): BC is free of 

Dutch Elm Disease, which is spread by bark 

beetles, such as the Native and European Elm 

Bark Beetles. The vectors do occur in BC. 

Beetles acquire the fungus in the fall when they 

tunnel under the bark of infected branches to 

breed. They spread the pathogen when they 

emerge and feed on new, young twigs. The first 

symptoms of disease are wilt and dieback of 

branches in mid-summer, often on only one 

side of the tree. Dark streaks can be found in 

the sapwood of infected branches. American 

elm is highly susceptible; Siberian and Chinese 

elm may become infected but do not wilt and 

die, so these resistant species rarely transmit 

the fungus. Other fungal diseases may cause 

branch dieback on elm with similar symptoms. 

Wet Wood or Slime Flux (Erwinia nimmipressuralis, 

and other bacteria): This bacterium is an invader 

of old, weakened or damaged trees and is a 

sign of other injury. It causes slimy, smelly 

cankers on trunks and branches and/or 

discolouration of interior wood. Exudate runs 

down the trunk causing further discolouration 

of the bark and attracts insects. It commonly 

affects old poplars, horse chestnuts and maples. 

Insects: 

Elm Leaf Beetle (Xanthogaleruca luteola): Attacks all 

elm species. The black, grub-like, larvae 

skeletonize the lower side of the leaf. Can lead 

to premature leaf drop. In the spring, the adult 

beetles lay yellow eggs in clusters on the 

underside of leaves. Larvae pupate on the 

ground at the base of the tree or in bark 

crevices. Adult beetles leave the tree to find a 

suitable overwintering site in the fall. 

European Elm Bark Beetle (Scolytus multistriatus): See 

Dutch Elm Disease (above). 

Woolly Apple Aphid (Eriosoma larigerum): This aphid 

causes clusters of rolled, twisted, and dwarfed 

leaves at the growing tip of elm shoots. Eggs 

overwinter on elm. After hatching in the 

spring, the insect then moves to apple, where it 

feeds on leaves and roots. It is present all 

summer. 




Tree Injection: 


ARBOTECT 20-S: See product label for application rate, etc. 

To control the disease-vectoring beetle, see European Elm Bark 

Beetle (below). 

Management: BC and Alberta remain free of Dutch Elm 

Disease. Rapid identification and removal of infected trees 

before beetles can breed in dead branches is essential to 

prevent its spread. Contact the Pacific Forestry Centre, 

Victoria, the Canadian Food Inspection Agency, or your local 

BCMA office immediately, if you observe wilt disease 

symptoms on an Ulmus tree. Do not bring Ulmus or Zelkova 

into BC. See British Columbia Plant Protection Regulations, 

Chapter 2 for information on the voluntary nursery 

certification program for the disease. Nurseries, parks and 

landscapers are advised to monitor American elm for dieback 

and prune out any dead or dying elm branches in the 

dormant season to prevent beetle breeding. 

Affected trees may die 

quickly, or limb by limb, and 

are a risk to fall down. Trees 

may be cleaned up to some 

extent by drilling holes just 

below the affected area and 

inserting plastic pipe to drain 

exudate from the trunk. An 

infected tree will eventually 

have to be cut down. 

ACECAP 97: for rate, see label or Aphids and Adelgids, 

Chapter 11. 

CONSERVE or SUCCESS 480 SC: 2.5 mL 

ENTRUST 80 W: 1.5 g 


sprayer = 637 g/1,000 L (do not apply to American elms) 

THIONEX EC: 125-175 mL 



Nursery: Apply insecticides to prevent beetle feeding. Follow 

a regular spraying and monitoring program. 

ACECAP 97: for rate, see label or Aphids and Adelgids, 

Chapter 11. 

INSECTICIDAL SOAP 47% or 50.5%: 2 L 

POUNCE 384 EC: 9 mL 


IMPOWER 60WP: See label. 

See General Insect and Mite Management: Aphids and Adelgids, 

Chapter 11. 



VIBURNUM 

Diseases: 

Powdery Mildew (Microsphaera spp.): Leaves become 

covered with white, powdery growth in late 

summer. The same fungus infects a wide range 

of woody, deciduous hosts. 

Insects: 

Viburnum Leaf Beetle (Pyrrhalta viburni): The larvae 

and adults both cause severe leaf 

skeletonization and defoliation of ornamental 

viburnums. Viburnum opulus is a preferred 

host, but it also causes moderate to slight injury 

on V. dentatum, V. lantana, V. tinus and V. 

trilobum. The viburnum leaf beetle has one 

generation per year. It overwinters as eggs, 

which are usually deposited in a straight row 

on the lower surface of 1- or 2-year-old twigs. 

The eggs hatch in the spring and the larvae 

begin to feed. In early summer, the larvae drop 

to the ground to pupate. Adult beetles emerge 

one month later. Female beetles will lay up to 

500 eggs from late summer to the first frost. 






ACTARA 25 WG: 280 g/ha 

CONSERVE 480 SC: 25 

mL/ha 


Fungicide applications are 

not usually warranted on 

landscape plants. Sulphur 

should not be used on 

Viburnum. See General Disease 

Management: Powdery Mildew, 

Chapter 9. 

To manage this pest prune 

out and destroy infested 

twigs after egg laying has 

stopped in the fall. 

See Appendix K for 

information on the 

susceptibility of Viburnum 

species to the viburnum leaf 

beetle.

Pests of Specific Crops

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