Elephant hawk moth, Large elephant hawk moth
Deilephila elpenor, the elephant hawk moth or large elephant hawk moth, is a moth in the family Sphingidae. Its common name is derived from the caterpillar's resemblance to an elephant's trunk. It is most common in central Europe and is distributed throughout the Palearctic region. It has also been introduced in British Columbia, Canada. Its distinct olive and pink colouring makes it one of the most recognisable moths in its range. However, it is quite easy to confuse the elephant hawk moth with the small elephant hawk moth, a closely related species that also shares the characteristic colours.
These moths are nocturnal and therefore feed on flowers that open or produce nectar at nighttime. The elephant hawk moth has very sensitive eyes that allow it to see colour even at low-light, and it was one of the first species in which nocturnal colour vision was documented in animals. The moth is also known for its hovering capability, which it utilises when feeding on nectar from flowers. This behaviour is costly in terms of energy and can help explain why the moth has evolved such enhanced visual capabilities for efficient feeding. The moths also have an important role as pollinators throughout their habitat.
The D. elpenor moth has olive-brown coloured forewings outlined with pink. Two pink lines also run through the wings. The first line is usually thicker and terminates in the center of the wings near a white dot. The second line, which runs below the first, starts at the white inner margins and runs until the tip of the wing. The hindwings have a black inner half that gradually turns pink from the middle outwards. It is outlined by white fringes. The head, thorax, and body are also olive-brown in colour with pink markings throughout.
D. elpenor is very common in central Europe and has a distribution throughout the palearctic region. The species is especially well-distributed in England, Wales, and Ireland. Until the 1980s, D. elpenor was only present in the southern half of Scotland, but now it has made its way up the north coast and into the country's mainland as well. In general, the moth's range becomes thinner and less concentrated in the northern parts of Europe. The range also extends throughout Asia and even to Japan.
D. elpenor inhabits a variety of habitats. These include rough grassland, heathland, sand dunes, hedgerows, woodland, the open countryside, and even urban gardens. The moths play an important role in pollination throughout their habitats. For example, previous studies on hawk moths have indicated that they can pollinate up to 5–10% of the tree and shrub species in the area they inhabit.
Peak flight time for D. elpenor is between the months of June and September. Since the species is nocturnal, the moth will fly from dusk until the morning. Then it will rest at one of its food sources until dusk comes again. The moth has a maximum flight speed of 4.5— 5.1 m/s. The wind confers mechanical resistance to the wings while flying. Therefore, winds have negative effects on the energy budget of the moth. As a result, D. elpenor stop visiting flowers at wind speeds starting at 3.0 m/s.
D. elpenor are particularly adept at hovering, which is a necessary skill for obtaining nectar. It utilises spatial cues and motion-detecting neurons to steady itself.
D. elpenor feed on nectar from flowers. When most insects forage, they land on the flower to retrieve the nectar. However, D. elpenor hovers in front of the flower rather than landing on the flower itself. The moth then extends its long, straw-like proboscis to attain its food. While hovering, its wings beat at a high frequency to stabilise the body from the drift of the wind. This flight pattern is quite costly; therefore, it is important for the moth to be able to feed effectively by knowing where to find nectar.
There is usually only a single generation of D. elpenor in a given year. Occasionally, a small number of second generation individuals in a single year will be recorded in the late summer, but this is very rare. The pupae overwinter in cocoons, and the species become active from May to early August. Its peak activity time is between the midsummer months of June and September.
