Deilephila elpenor

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Elephant hawk moth
Deilephila elpenor 04.jpg
Dorsal or upperside view
Elephant hawkmoth (Deilephila elpenor) male.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Sphingidae
Genus: Deilephila
Species:
D. elpenor
Binomial name
Deilephila elpenor
Synonyms
  • Sphinx elpenorLinnaeus, 1758
  • Chaerocampa lewisiiButler, 1875
  • Elpenor vitisOken, 1815
  • Chaerocampa elpenor alboradiataLambillion, 1913
  • Chaerocampa elpenor cinerescensNewnham, 1900
  • Deilephila elpenor argenteaBurrau, 1950
  • Deilephila elpenor philippsiNiepelt, 1921
  • Deilephila elpenor tristisLempke & Stolk, 1986
  • Deilephila elpenor vautriniAustaut, 1907
  • Eumorpha elpenor claraTutt, 1904
  • Eumorpha elpenor obsoletaTutt, 1904
  • Eumorpha elpenor pallidaTutt, 1904
  • Eumorpha elpenor unicolorTutt, 1904
  • Eumorpha elpenor virgataTutt, 1904
  • Pergesa elpenor daubiNiepelt, 1908
  • Pergesa elpenor distinctaMeyer, 1969
  • Pergesa elpenor hadesRebel, 1910
  • Pergesa elpenor lugensNiepelt, 1926
  • Pergesa elpenor scheiderbaueriGschwandner, 1924
  • Pergesa elpenor szechuanaChu & Wang, 1980

Deilephila elpenor, the elephant hawk moth or large elephant hawk moth, [2] is a moth in the family Sphingidae. Its common name is derived from the caterpillar's resemblance to an elephant's trunk. [3] It is most common in central Europe and is distributed throughout the Palearctic region. [4] 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. [5] 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. [6]

Contents

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. [7] The moth is also known for its hovering capability, which it utilises when feeding on nectar from flowers. [8] This behaviour is costly in terms of energy and can help explain why the moth has evolved such enhanced visual capabilities for efficient feeding. [7] The moths also have an important role as pollinators throughout their habitat. [9]

Description

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. [10]

Subspecies

Two separate subspecies, Deilephila elpenor elpenor and Deilephila elpenor lewisii, were recognised in the past, but they are no longer regarded as well-distinguished. Similarly, the subspecies Deilephila elpenor szechuana is now thought to be a synonym for Deilephila elpenor elpenor. The subspecies Deilephila elpenor macromera, found in southern China, northern India, Bhutan and Myanmar, is still regarded as distinct. [11]

Similar species

The elephant hawk moth is often confused with the small elephant hawk moth (Deilephila porcellus). There are clear distinctions in size and colouring that can help differentiate between the two. As the name suggests, the small elephant hawk moth is much smaller. It is also more yellow in colour around its body. The most obvious defining feature is the thick pink stripe going down the elephant hawk moth's abdomen that is missing on the small elephant hawk moth's abdomen. The two species are not usually seen together in garden traps because the small elephant hawk moth prefers more open habitats. [6]

Range

D. elpenor is very common in central Europe and has a distribution throughout the palearctic region. [4] 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. [5] 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. [10]

Habitat

D. elpenor inhabits a variety of habitats. These include rough grassland, heathland, sand dunes, hedgerows, woodland, the open countryside, and even urban gardens. [5] 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. [9]

Life cycle

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. [5]

Egg Deilephila elpenor - egg 1 (HS).JPG
Egg

Egg

The females lay eggs either singly or in pairs on the leaves of plants that can act as food sources to the caterpillars when they emerge. These include but are not limited to rosebay willowherb ( Chamaenerion angustifolium) and bedstraws (of the genus Galium ). [12] The moths are also attracted to gardens, and eggs have frequently been found on garden fuchsias, dahlias, and lavender. The eggs are whitish-green and have a glossy texture. [10] Eggs will usually hatch in ten days. [12]

Larva

Larva Deilephila elpenor caterpillar.jpg
Larva
Deilephila elpenor caterpillar resembling the trunk of an elephant Deilephila elpenor Groot avondrood rups.jpg
Deilephila elpenor caterpillar resembling the trunk of an elephant

Young larvae are a yellowish white to green colour. When they have finished growing, the larvae are a brown-gray colour with black dots along the length of the body. Larvae have a backward curving spine or "horn" that is the same colour as their body on the final abdominal segment. Fully grown larvae can measure up to 3 inches (7.62 cm) in length. [10] They also weigh somewhere between 4 and 7.5 grams (0.14 and 0.26 oz); during their lifetime, they ingest a total of 11–30 grams (0.39–1.06 oz) of plant material. [13]

Variation in colour has been observed in nature. Specifically, a green version of the full-grown larva exists within the species. Previous research has shown that the colour variation is not due to a simple inheritance pattern, and specific explanations still remain inconclusive. [14]

Pupa

Pupa Deilephila elpenor chrysalis 01.JPG
Pupa

It takes around 27 days for D. elpenor to move from the larva stage to the pupa stage. [13] When the larvae are fully grown, they will look for a place to pupate. Usually, this ends up being at the base of a plant in plant debris or underneath the surface of the ground. Once they have found a secure spot, they will line the pupal chamber with a few strands of silk, pupate, then overwinter as pupae. Their pupae are brown with darker brown speckles throughout, and the divisions between the segments appear black. [10] Pupae are 40–45 mm long. [15]

Adult

The wingspan of D. elpenor that have been collected in Europe measure to be around 60–70 mm. [15] There is also very little variation between the male and female D. elpenor. [5] Adults are the most active during the month of June. They visit flowers and feed on the nectar at night, and are especially attracted to plants such as honeysuckles (Lonicera). [10]

Adaptations

Eyespots

Many Lepidoptera species have evolved eyespots either on their body (when they are caterpillars) or on their wings (as fully grown adults). This dark, circular marking is generally thought to resemble the eyes of a predator and deter attacks from birds that feed on insects. This mimicry is effective because the caterpillar is usually somewhat concealed, and because the predators must respond to the signals quickly. [16]

When it feels threatened by a predator, the caterpillar will widen the anterior part of the body. This defensive posture emphasises the eyespots and makes it more conspicuous. Some research have suggested that this allows the eyespots of the caterpillar to resemble a snake more closely than it could when it is at rest. [16]

Mating

Pheromones

Experiments using gas chromatography and mass spectroscopy have identified (E)-11-hexadecenal and (10E, 12E)-10,12-hexadecadienal [(E,E)-bombykal] as the major components of the female sex pheromone. These pheromones are the most active when females are actively exhibiting calling behaviour and visibly showing their ovipositors. [4]

Vision

D. elpenor have very sensitive eyes that allow them to have colour vision even at nighttime. [7] Studies have analysed the dark-adapted eyes of D.elpenor and have found three visual pigments with a maximal wavelength of 345 nm, 440 nm, and 520 nm. These values respectively correspond to ultraviolet, blue, and green wavelengths. [17] Most vertebrates, such as humans, lose the ability to use the three types of photoreceptors present in the eye in dim light conditions. However, all three types of photoreceptors remain functional in various light conditions for D. elpenor, giving it the ability to have scotopic colour vision. [18] This species was the first instance in which being able to see colour at night was documented in animals. [7] Usually, increased colour sensitivity results in decreases in spatial resolution. [19] However, despite the great sensitivity of its eyesight, the moth also has a reasonable spatial resolution. This nighttime colour vision is necessary because of the moth's feeding patterns. D. elpenor feeds at the darkest hours of night and also hovers over the flower to suck its nectar out rather than sitting on the flower. Locating the correct flower and hovering over it are both visually demanding tasks. [7]

Feeding

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. [8]

Visual cues

Since they are nocturnal, the moths tend to feed on flowers that open or produce nectar at twilight or during the night. These are commonly termed "hawkmoth flowers". [9] D. elpenor are able to see colour, an ability that is usually absent from most other nocturnal species. [19] Their particular visual system allows them to discriminate between various wavelengths even at low illumination, allowing the moths to find correct food sources while foraging. [9]

Olfactory cues

Olfaction also plays an important role in feeding for the moth. Many of the hawkmoth flowers contain a pleasant smell. Previous studies have found that fragrance release from the hawkmoth flowers stimulate flower-seeking behaviour by the moths. Therefore, it has been hypothesized that both visual and olfactory cues play a role in the feeding behaviour of D. elpenor. [9]

Learning

D. elpenor, like many other insects, can learn to adapt its behaviour to changing environmental conditions. Experiments with D. elpenor has shown that it can discriminate between various visual stimuli (i.e. colour) and associate it with a food reward. This behaviour is especially important because the wrong decision when choosing a food source can prove to be a costly mistake in terms of time and energy resources. The experiment was conducted through the use of differently coloured artificial flowers. When no reward in the form of nectar was given by the flower, the moth did not further participate in foraging behaviour with that particular flower. This demonstrated the moth's need to keep energy expenses as low as possible while foraging. [8]

Flight

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. [5] 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. [20]

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. [21]

Predators

Some natural predators use bright colouring to attract its prey, which includes D. elpenor. The conspicuous body colouring of certain nocturnal invertebrates, such as the white forehead stripes on the brown huntsman spider, lures the flying moth to its predator. [22]

Bats are also known to prey on the moth. [23]

Related Research Articles

<span class="mw-page-title-main">Lepidoptera</span> Order of insects including moths and butterflies

Lepidoptera is an order of insects that includes butterflies and moths. About 180,000 species of the Lepidoptera are described, in 126 families and 46 superfamilies, 10 percent of the total described species of living organisms. It is one of the most widespread and widely recognizable insect orders in the world. The Lepidoptera show many variations of the basic body structure that have evolved to gain advantages in lifestyle and distribution. Recent estimates suggest the order may have more species than earlier thought, and is among the four most species-rich orders, along with the Hymenoptera, Diptera, and Coleoptera.

<span class="mw-page-title-main">Hummingbird hawk-moth</span> Species of moth

The hummingbird hawk-moth is a species of hawk moth found across temperate regions of Eurasia. The species is named for its similarity to hummingbirds, as they feed on the nectar of tube-shaped flowers using their long proboscis while hovering in the air; this resemblance is an example of convergent evolution.

<span class="mw-page-title-main">Sphingidae</span> Family of insects

The Sphingidae are a family of moths (Lepidoptera) called sphinx moths, also colloquially known as hawk moths, with many of their caterpillars known as “hornworms”; it includes about 1,450 species. It is best represented in the tropics, but species are found in every region. They are moderate to large in size and are distinguished among moths for their agile and sustained flying ability, similar enough to that of hummingbirds as to be reliably mistaken for them. Their narrow wings and streamlined abdomens are adaptations for rapid flight. The family was named by French zoologist Pierre André Latreille in 1802.

<span class="mw-page-title-main">Death's-head hawkmoth</span> Species of moth

The name death's-head hawkmoth refers to any of three moth species of the genus Acherontia. The former species is found in Europe and throughout Africa, the latter two are Asian; most uses of the common name refer to the European species. These moths are easily distinguishable by the vaguely human skull-shaped pattern of markings on the thorax. They are large nocturnal moths with brown and yellow or orange coloring, and all three species are fairly similar in size, coloration and life cycle.

<i>Deilephila</i> Genus of moths

The genus Deilephila is part of the family Sphingidae, the hawk-moths or sphinxes. The genus was erected by Jakob Heinrich Laspeyres in 1809. It consists of a small number of Palearctic species most of which have common names involving the phrase "elephant hawk moth". They include the elephant hawk moth, Deilephila elpenor; the small elephant hawk moth and the Chitral elephant hawk moth. The oleander hawk moth is sometimes classified in this genus as D. nerii, but sometimes treated in genus Daphnis.

<i>Manduca quinquemaculata</i> Species of moth

Manduca quinquemaculata, the five-spotted hawkmoth, is a brown and gray hawk moth of the family Sphingidae. The caterpillar, often referred to as the tomato hornworm, can be a major pest in gardens; they get their name from a dark projection on their posterior end and their use of tomatoes as host plants. Tomato hornworms are closely related to the tobacco hornworm Manduca sexta. This confusion arises because caterpillars of both species have similar morphologies and feed on the foliage of various plants from the family Solanaceae, so either species can be found on tobacco or tomato leaves. Because of this, the plant on which the caterpillar is found does not indicate its species.

<i>Agrius cingulata</i> Species of moth

Agrius cingulata, the pink-spotted hawkmoth or sweetpotato hornworm, is a moth in the family Sphingidae. The species was first described by Johan Christian Fabricius in 1775.

<i>Agrius convolvuli</i> Species of moth

Agrius convolvuli, the convolvulus hawk-moth, is a large hawk-moth. It is common throughout Europe, Asia, Africa, Australia and New Zealand, partly as a migrant. In New Zealand, it is also known as the kumara moth, and in the Māori language as hīhue.

<i>Daphnis nerii</i> Species of moth

Daphnis nerii, the oleander hawk-moth or army green moth, is a moth of the family Sphingidae. It was described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.

<i>Acherontia atropos</i> Species of moth

Acherontia atropos, the Africandeath's-head hawkmoth, is the most widely recognized of three species within the genus Acherontia. It is most commonly identified by the vaguely skull-shaped pattern adorning the thorax, the characteristic from which its common and scientific names are derived. The species was first given its scientific name by Carl Linnaeus in his 1758 10th edition of Systema Naturae.

<span class="mw-page-title-main">Saddleback caterpillar</span> Larva of an eastern North American moth

The saddleback caterpillar is the larva of a species of moth native to eastern North America. It is also found in Mexico. The species belongs to the family of slug caterpillars, Limacodidae.

<i>Smerinthus ocellatus</i> Species of moth in the family Sphingidae

Smerinthus ocellatus, the eyed hawk-moth, is a European moth of the family Sphingidae. The species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.

<i>Hyles gallii</i> Species of moth

Hyles gallii, the bedstraw hawk-moth or galium sphinx, is a moth of the family Sphingidae. The species was first described by S. A. von Rottemburg in 1775.

<i>Daphnis hypothous</i> Species of moth

Daphnis hypothous, the jade hawkmoth, is a moth of the family Sphingidae described by Pieter Cramer in 1780. It is known from Sri Lanka, southern and northern India, Nepal, Myanmar, southern China, Taiwan, Thailand, Malaysia, and Indonesia. It is a rare vagrant to the Western Palaearctic realm. During the last hundred years a number have been discovered within the Middle East and one was even found in Scotland late in the 20th century but this was probably imported as a pupa with cargo.

<i>Hyles lineata</i> Species of moth

Hyles lineata, also known as the white-lined sphinx, is a moth of the family Sphingidae. They are sometimes known as the hummingbird moth because of their bird-like size and flight patterns.

<span class="mw-page-title-main">Eyespot (mimicry)</span> Eye-like marking used for mimicry or distraction

An eyespot is an eye-like marking. They are found in butterflies, reptiles, cats, birds and fish.

<i>Acherontia lachesis</i> Species of moth

Acherontia lachesis, the greater death's head hawkmoth or bee robber, is a large sphingid moth found in India, Sri Lanka and much of the Oriental region. It is one of the three species of death's-head hawkmoth genus, Acherontia. The species was first described by Johan Christian Fabricius in 1798. It is nocturnal and very fond of honey; they can mimic the scent of honey bees so that they can enter a hive unharmed to get honey. Their tongue, which is stout and very strong, enables them to pierce the wax cells and suck the honey out. This species occurs throughout almost the entire Oriental region, from India, Pakistan and Nepal to the Philippines, and from southern Japan and the southern Russian Far East to Indonesia, where it attacks colonies of several different honey bee species. It has recently become established on the Hawaiian Islands.

<i>Deilephila porcellus</i> Species of moth

Deilephila porcellus, the small elephant hawk-moth, is a moth of the family Sphingidae. The species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.

<span class="mw-page-title-main">External morphology of Lepidoptera</span> External features of butterflies and moths

The external morphology of Lepidoptera is the physiological structure of the bodies of insects belonging to the order Lepidoptera, also known as butterflies and moths. Lepidoptera are distinguished from other orders by the presence of scales on the external parts of the body and appendages, especially the wings. Butterflies and moths vary in size from microlepidoptera only a few millimetres long, to a wingspan of many inches such as the Atlas moth. Comprising over 160,000 described species, the Lepidoptera possess variations of the basic body structure which has evolved to gain advantages in adaptation and distribution.

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