Ant lions (Myrmeleontidae family)
There are 1000 species worldwide, found in semi-arid areas. There is just one British species, Euroleon nostras, found in East Anglia and around the south coast of England, and also in the Channel Islands.
Larvae. The most remarkable feature of ant lions is the pit fall trap the larva constructs to capture its prey. Left is a Myrmeleon formicarius pit fall trap with just the jaws of the larva visible, and on the right is the fat, hairy larva. The larva constructs the trap in loose sand, by shuffling backwards in a circle, and flicking the excavated sand over its head.
Once the trap is dug it waits with just its jaws on the outside for an insect to fall into the trap and slide to the bottom. The jaws are huge and perforated so the larva can inject digestive enzymes to soften the tissues, then suck the juices of its victims. The most common victims are ants - hence its common name.
If the victim puts up a fight the ant lion will either drag it under the sand or whack it against the side of the trap until it is subdued. Any victim falling into the trap and trying to get out will be bombarded with sand to try to make it lose its footing.
Common pitfall trap locations are cave entrances, under overhanging rocks, and around human habitations. The larva is a curious beast, it cannot walk forwards, but only backwards. Also it never emits any faeces until it is ready to emerge from its chrysalis which can be 1 - 2 years after hatching from the egg. Then it emits the accumulated faeces.
Ant lion communities? Ant lion larva have very specific habitat requirements - fine sand or dust, dry and sheltered from rain. As these areas are hard to find some suitable areas appear to be populated by a community of ant lion larvae. However there is no interaction between the various larvae - they are there because of the lack of suitable habitat elsewhere.
The ant lion adults resemble dragonflies and lacewings, but have thicker, clubbed antennae. Adults are not strong fliers and tend to fly at night. They are seen in sandy areas in southern Europe from June - August. Adults are also carnivorous, living off smaller insects that they find crawling over vegetation. Myrmeleon formicarius (above) has a wing span of 35 mm and resembles a lacewing or a dull-coloured damselfly, but with long antennae. It flies at night in June and July.
Its eggs are laid singly or in groups in dry, sandy soil.
Snakeflies are sometimes put in an Order of their own; the Raphidoptera. The snakefly gets its name from its long neck and its method of catching prey, (usually soft-bodied insects) by raising its head and lunging. There are about 225 species world wide, 75 in Europe, and 4 in Britain.
In the UK they are usually found in wooded or shady areas, and prefer pine and oak trees, where their favourite food is aphids. Adults are found from May - July. After pupating the adults fly to the tree tops to feed on aphids, and so are seldom seen by us. Unusually, during mating the male is under the female. Females have a long ovipositor to lay their eggs in the crevices of bark on dead and decaying trees.
The larvae live in the burrows of wood-boring beetles, and feed on the grubs they find inside the tree. The larvae can be parasitised by ichneumonid wasps. Pupation takes place in debris either at the foot of the tree, or bark surface. In the U. K. the life cycle usually takes 2 years.