ONE of the aspects to working with wildlife is that no matter how long you seem to do the job there is always something new to discover, every so often something will be brought to your attention that you knew was residing on one of the sites, but had simply never encountered.

Recently I received an email from one of our volunteers. It showed them holding an enormous caterpillar that they had found wandering across a footpath. The volunteer was really concerned that it would be trodden on, but was also fascinated to know what it was. As soon as I saw it I knew exactly what this unusual creature was, an elephant hawk moth. I have only seen the caterpillar once before, and the adult only twice, but it is so distinctive, it cannot be confused with anything else.

At around 80mm in length and being quite stocky it is one of the largest caterpillars you are likely to encounter in the UK, in fact it is one of the largest insects you are likely to encounter here also.

Its colour varies from a pale ochre to bright green and it displays a horn-like protrusion on its rear end. It is the head-end of the body that makes this caterpillar so unusual, just behind its head it has four large pale spots with dark centres, often called eye-spots. When the creature is threatened by a predator, it raises its head off the ground and pulls it in towards its body.

This makes the area with the eye-spots swell, while doing this it sways to and fro menacingly, some say giving the caterpillar a snake-like appearance. Truly one of the wonders of the animal kingdom though certainly not one of the insect world’s beauties. The adult however is quite the opposite, and is strikingly beautiful. One of the UK’s largest moth species, its body and wings are awash with stripes of olive/green and shocking pink. It can occasionally be seen at dusk, sipping the nectar from honeysuckle, but for such a large insect it is a fairly rare sight.

The way the elephant hawk moth caterpillar uses mimicry to defend itself is not at all unusual in the insect world, in fact there are many other caterpillars that do so. One example is the puss moth, although I think this insect uses its strange appearance to startle predators than actually mimicking another creature.

When disturbed it rears up its large head and tail and its last pair of legs are highly modified into long whip-like structures which it waves about over its back, a very odd sight.

Possibly the strangest of all the UK’s caterpillars is that of the lobster moth.

It is a rare sight and is usually found only in mature forests, where it feeds on beech. Upon first sight, the last thing you would wish to do is touch, let alone pick up this peculiar creature. Its front legs have developed to become long and spindly, its head is quite large, body is slim and heavily ridged, while its rear quarters are swollen and held folded up over it's back. To top this off, it also has two long projections sprouting from its tail-end that are held aloft when it curls over its rear.

A truly bizarre animal which resembles a crustacean or perhaps a scorpion much more than any insect.

By ADAM HAMILTON