Moths of Britain and
Superfamily - BOMBYCOIDEA
Family - SPHINGIDAE
Deilephila elpenor, Stansted Forest,
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.
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 &
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.
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.
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.
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.