Elephant Hawk Moth Facts

The elephant hawk moth (Deilephila elpenor) gets its common name for the caterpillar's resemblance to an elephant's trunk. Hawk moths are also known as sphinx moths because the caterpillar resembles the Great Sphinx of Giza when resting, with legs held off the surface and head bowed as if in prayer.

Description

The elephant hawk moth starts life as a glossy green egg that hatches into a yellow or green caterpillar. Eventually, the larva molts into a brownish-gray caterpillar with spots near its head and a backward curving "horn" at the back. Fully grown larvae measure up to 3 inches long. The caterpillar forms a speckled brown pupa that hatches into the adult moth. The moth measures between 2.4 and 2.8 inches in width.

While some hawk moths display dramatic sexual dimorphism, male and female elephant hawk moths are difficult to distinguish. They are the same size as each other, but the males tend to be more deeply colored. Elephant hawk moths are olive brown with pink wing margins, pink lines, and a white dot on the top of each forewing. The head and body of the moth are olive brown and pink, too. While a hawk moth does not have particularly feathery antennae, it does have an extremely long proboscis ("tongue").

The large elephant hawk moth may be confused with the small elephant hawk moth (Deilephila porcellus). The two species share a common habitat, but the small elephant hawk moth is smaller (1.8 to 2.0 inches), more pink than olive, and has a checkerboard pattern on its wings. The caterpillars look similar, but the small elephant hawk moth larvae lack a horn.

Habitat and Distribution

The elephant hawk moth is particularly common in Great Britain, but it occurs throughout the palearctic region, including all of Europe and Asia as far east as Japan.

Diet

Caterpillars eat a variety of plants, including rosebay willowherb (Epilobium angustifolium), bedstraw (genus Galium), and garden flowers, such as lavender, dahlia, and fuchsia. Elephant hawk moths are nocturnal feeders that forage for flower nectar. The moth hovers over the flower rather than landing on it and extends its long proboscis to suck up nectar.

Behavior

Because they need to find flowers at night, elephant hawk moths have exceptional color vision in the dark. They also use their sense of smell to find food. The moth is a swift flyer, attaining speeds up to 11 mph, but it cannot fly when it's windy. It feeds from dusk until dawn and then rests for the day near its final food source.

The elephant hawk moth larva might look like an elephant's trunk to people, but to predators it more likely resembles a small snake. Its eye-shaped markings help ward off attacks. When threatened, the caterpillar swells up near the head to enhance the effect. It can also eject the green contents of its foregut.

Reproduction and Offspring

Many species of hawk moth produce multiple generations in a single year, but the elephant hawk moth completes one generation per year (rarely two). Pupae overwinter in their cocoons and metamorphose into moths in late spring (May). The moths are most active in midsummer (June to September).

The female secretes pheromones to indicate readiness to mate. She lays her green to yellow eggs singly or in pairs on a plant that will be the caterpillar's food source. The female dies shortly after laying eggs, while the males live a bit longer and may mate additional females. The eggs hatch in about 10 days into yellow to green larvae. As the larvae grow and molt, they become 3-inch spotted gray caterpillars that weigh between 0.14 and 0.26 ounces. About 27 days after hatching from an egg, the caterpillar forms a pupa, usually at the base of a plant or in the ground. The speckled brown pupae are around 1.5 inches long.

Conservation Status

The International Union for Conservation of Nature (IUCN) has not assigned a conservation status to the elephant hawk moth. The species is threatened by pesticide use, but is common throughout its range.

Elephant Hawk Moths and Humans

Hawk moth caterpillars are sometimes regarded as agricultural pests, yet the moths are important pollinators for many types of flowering plants. Despite the moth's bright coloring, neither the caterpillar nor the moth bite or are toxic. Some people keep the moths as pets so they can watch their fascinating hummingbird-like flight.

Sources

• Hossie, Thomas John and Thomas N. Sherratt. "Defensive posture and eyespots deter avian predators from attacking caterpillar models." Animal Behaviour. 86 (2): 383–389, 2013. doi:10.1016/j.anbehav.2013.05.029
• Scoble, Malcolm J. The Lepidoptera: Form, Function and Diversity (2nd ed.). Oxford University Press & Natural History Museum London. 1995. ISBN 0-19-854952-0.
• Waring, Paul and Martin Townsend. Field Guide to the Moths of Great Britain and Ireland (3rd ed.). Bloomsbury Publishing. 2017. ISBN 9781472930323.
• Warrant, Eric. "Vision in the dimmest habitats on Earth." Journal of Comparative Physiology A. 190 (10): 765–789, 2004. doi:10.1007/s00359-004-0546-z
• White, Richard H.; Stevenson, Robert D.; Bennett, Ruth R.; Cutler, Dianne E.; Haber, William A. "Wavelength Discrimination and the Role of Ultraviolet Vision in the Feeding Behavior of Hawkmoths." Biotropica. 26 (4): 427–435, 1994. doi:10.2307/2389237