Moths of
Britain and Europe
Elephant Hawkmoth
Deilephila elpenor
LINNAEUS, 1758
Family - SPHINGIDAE
subfamily -
MACROGLOSSINAE
Tribe -
introduction
|
habitats |
lifecycle |
adult behaviour
Elephant Hawkmoth
Deilephila elpenor, Stansted
Forest, England
Introduction
The
family Sphingidae comprises of in excess of 1050 species worldwide. The moths
are generally large in size ( up to 20cms across the wings in the case of the
South American Cocytius cluentus ) and are very
adept and powerful fliers with the ability to hover, and to fly backwards and
sideways with ease.
The Elephant Hawkmoth
Deilephila elpenor,
and Small Elephant
Hawkmoth D. porcellus, are both resident British
species. They, together with the Bee Hawkmoths, Hummingbird Hawkmoth, Spurge
Hawkmoth and Silver-striped Hawkmoths are members of the subfamily
Macroglossinae - a group of moths renowned for having very long tongues that can
reach into the deepest of flowers. The enormous Central American hawkmoth
Amphimoea walkeri has the distinction of having the
longest tongue ( proboscis ) of any known moth - it measures an amazing 30cms in
length !
There
are 6 members of the genus Deilephila, of which 2
are found in Europe - elpenor &
porcellus.
Deilephila elpenor is the larger and more beautiful of the 2 European
species, and is common and widespread in southern Britain, but rarer in the
north.
The moth gets its common name
from the appearance of its caterpillar, which has been compared to the trunk of
an elephant.
Habitats
This species is found in a variety of habitats including grassland, forest
clearings, along hedgerows, and other places where its larval foodplant grows in profusion.
Lifecycle
The moths emerge in June and lay their smooth, pale green
eggs singly on leaves of the foodplants greater willowherb
Epilobium hirsutum ( Onagraceae ).
The caterpillar is
brownish-grey, marked with a network of fine dark lines, much like the folds in
the skin of an elephant's trunk. When it walks, the caterpillar habitually sways
the front segments from side to side, again reminiscent of the movement of an
elephant's trunk. The anal segment bears a short horn. The first
two abdominal segments each bear a pair of pink and black eye-like markings. If
the caterpillar becomes alarmed, it retracts its head, which compresses the
thoracic segments and causes these "false eyes" to expand. This gives the
caterpillar a snake-like appearance, which presumably acts as a deterrent to
predators.
The pupa is pale brown,
freckled with dark brown. It is formed among withered leaves and bits of stem,
on the surface of the ground.
Adult behaviour
The moths fly at dusk and the early part of the night, and in
common with other hawkmoths have a very rapid wing-beat which
enables them to fly swiftly, producing a soft whirring sound as
they pass by. They are able to vary the angle of their forewings
while flying, which gives them the ability to swerve with great
agility, or to hover in front of their favourite nectar source -
honeysuckle flowers.
Elephant Hawkmoths have been studied
to determine whether or not nocturnal moths can perceive colour.
Kelber et al found that this species has
9 light sensors in each
ommatidium ( compared to between 2 - 6 in butterflies ); and used
behavioural experiments to prove that the moths are able to
discriminate coloured stimuli at intensities corresponding to dim
starlight.
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