Prociphilus bumeliae and Prociphilus fraxini (Ash leaf-nest aphids) identification, images, ecology, control

In spring the fundatrices of Prociphilus bumeliae and Prociphilus fraxini are brown, covered with white wax wool, and form loose leaf-nests on their primary host, usually ash (Fraxinus species). The first image below shows a mature colony. Prociphilus bumeliae and Prociphilus fraxini both have distinct wax glands on the head and thorax, as well as large, albeit indistinct wax glands on the abdomen. The 5-segmented antennae are about a third of the length of the body. There are no siphunculi.

Mature colony of Prociphilus (ash leaf-nest aphids) in leaf nest on Fraxinus excelsior (ash) in Hungary

Alates (see second picture above) have a blackish-brown head and thorax, and a light brown or yellowish red abdomen, more or less covered with white wax wool. The 6-segmented antennae are about half the length of the body.

Prociphilus bumeliae and Prociphilus fraxini can only be distinguished at the alate stage produced in the leaf nest.

In the Prociphilus bumeliae alate the third antennal segment is more than five times longer than the second antennal segment. Also the head has only a pair of posterior dorsal wax pore plates which are conspicuous as clearly defined pale areas much larger than the ocelli.
In the Prociphilus fraxini alate the third antennal segment is usually less than five times longer than the second antennal segment. The posterior wax pore plates on the head are ill-defined, but there is usually a pair of small clear anterior wax pore plates.

Both these Prociphilus species host alternate from ash (Fraxinus) to fir (Abies). Prociphilus bumeliae sometimes also uses privet (Ligustrum vulgare) or Common lilac (Syringa vulgaris) as a primary host. The fundatrices colonize the base of the primary host. Their offspring feed on the young shoots and petioles inducing the formation of leaf nests often high in the trees. These develop into alatae, which migrate to the roots of fir. In October sexuparae develop on fir, and migrate back to ash where the sexual forms are produced.

Biology & Ecology:

Both these aphids may also form colonies on the bark of the stem or branches (see picture below), rather than leaf nests.

Prociphilus (ash leaf-nest aphids) on branch of Fraxinus excelsior (ash) in Hungary

Prociphilus fraxini and Prociphilus bumeliae are usually densely covered with wax. The white patches of wax mark the positions of the wax glands. Wax protected aphids are usually not ant-attended.

Prociphilus (ash leaf-nest aphids) with excreted honeydew on Fraxinus ornus (manna ash) in Hungary

However, these two Prociphilus are sometimes ant attended. When they are, Way, 1963 reported the ants remove the wax - a surprising observation given wax is repellent to most insects. It seems more likely these two Prociphilus, like many other wax-covered aphids, simply cease wax-production when ant attended. If the ants really do remove it, then we have to ask why they should do so. Perhaps the wax has some nutritional value for the ants, or possibly wax may diminish the aphid honeydew responses to tending by the ant. The picture below shows ant attended Prociphilus, with much of the colony still densely coated in wax.

Prociphilus (ash leaf-nest aphids) attended by ants on Fraxinus excelsior (common ash) in Hungary

The picture below shows another part of the colony which has rather little wax, presumably removed by the ants.

Prociphilus (ash leaf-nest aphids) dewaxed by ants on Fraxinus excelsior (common ash) in Hungary

Other aphids on the same host:

Primary hosts

Prociphilus fraxini and/or Prociphilus bumeliae have been recorded from 4 Fraxinus species (Fraxinus angustifolia, Fraxinus excelsior, Fraxinus mandshurica, Fraxinus ornus). Blackman & Eastop list only 9 species of aphids as feeding on ash worldwide, and provide formal identification keys for aphids on Fraxinus.
Blackman & Eastop list 6 species of aphid as feeding on European ash (Fraxinus excelsior) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 3 as occurring in Britain (Show British list).
Blackman & Eastop list 6 species of aphid as feeding on privet (Ligustrum vulgare) (Show World list), all of which Baker (2015) lists as recorded in Britain (Show British list).
Blackman & Eastop list 5 species of aphid as feeding on common lilac (Syringa vulgaris) (Show World list), 2 of which Baker (2015) lists as recorded in Britain (Show British list).

Secondary hosts

Prociphilus fraxini and/or Prociphilus bumeliae have been recorded from 7 Abies species.

Blackman & Eastop list 47 species of aphid as feeding on true firs (Abies species) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 11 as occurring in Britain (Show British list).

Acknowledgements

We especially thank Dr László Érsek for the images shown above.
Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994) and Blackman & Eastop (2006) supplemented with Blackman (1974), Stroyan (1977), Stroyan (1984), Blackman & Eastop (1984), Heie (1980-1995), Dixon & Thieme (2007) and Blackman (2010). We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure provided by Blackman & Eastop (2006).

Useful weblinks

Prociphilus bumeliae & Prociphilus fraxini

Ash leaf-nest aphids

Identification & Distribution

Biology & Ecology:

Other aphids on the same host:

Primary hosts

Secondary hosts

Acknowledgements

Useful weblinks