Drive to look out for beetles

BEETLES are by far our biggest group of insects; they come in all shapes and sizes and fit in to pretty much every part of the food chain - although none are top predators and all are harmless to humans.

There are around 4,200 species of beetle in the UK.

Many are picky about where they live and what they eat, but as a group, beetles are found nearly everywhere and eat … well almost anything including dung, dead wood and timber, fungi, plants, other insects and dead animals. There are a few we see as pests - eating the 'wrong' things - but mostly beetles are useful to us eating the 'right' things, pollinating plants or generally tidying up.

Beetles have a four stage life cycle. Adults lay eggs which hatch into larvae. These may be dumpy-legged or legless grubs, or leggy hunters. Each larva feeds and grows, shedding its skin several times before becoming a pupa. Unlike a moth or butterfly chrysalis, the pupa is soft and white with the developing legs, wing-cases and antennae sticking out - so it has to be protected somewhere, often in a 'cell' in the soil which the larva prepares before pupating. At the right time of year, the pupa hatches into an adult beetle.

Stag beetles, the UK's largest, can be seen around this time of year flying in many of our parks and hedgerows especially at dusk after a warm day. Most records of stag beetles come from southern Suffolk. The lesser stag beetle is more widely distributed. The creamy white C-shaped orange headed grubs of the lesser stag eat soft rotted wood especially in old ash and apple trees. They usually take two years to turn into adults which you're most likely to find near an outside light.

The wasp beetle has a similar life story, but the adult - which as its name suggests mimics a wasp - feeds on nectar and pollen and is most commonly found on flowers in the daytime. The flat creamy orange grubs of the cardinal beetle live in dead wood too, but feed on other insects such as beetle grubs! Adult cardinal beetles are bright red and are usually seen on leaves or flowers, sometimes on tree trunks.

Cardinal and soldier beetles, ladybirds and many others are brightly coloured to warn potential predators that they're poisonous and taste vile! Because of its shiny red spots, the sap beetle is also known as a false ladybird. It likes to feed at night on oozing sap or rotting fruit and you might find it on your compost heap.

When the green tortoise beetle is disturbed it pulls itself flat to the leaf like a suction cup. After a while it peeps, first with antennae then with its head, before letting go. Its larva which also eats leaves, holds a sack of poo over its back to put off hungry birds! Other leaf eaters include the metallic green nettle weevil, the chunky thighed, jumping blue flea beetle and the dock leaf beetle - the female of which resembles a living marble when full of eggs!

The devils coach horse has a sinister name and some pretty horrid habits. After hunting down other invertebrates - such as caterpillars - and catching them in its jaws, it vomits into the bite, mixing some of its previous meal with the new corpse to help digestion. When threatened it cocks its abdomen, sprouts two yellow glands and makes a nasty smell. Like the torpedo rove beetle, violet ground beetle and black clock, it hunts at night and hides by day. In contrast, the big-eyed bronze ground beetle, the greenfly-eating ladybirds and most metallic coloured beetles hunt mostly by day. All these species are adapted to catch slightly different prey and are useful garden pest controllers.

Soldier and malachite beetles are fierce predators that lurk in flowers and grab other insects visiting to feed. Adult thick-legged flower beetles, click beetles, nettle catkin weevils and pollen beetles also live on flowers but feed on nectar and pollen. Pollen beetles are really tiny but may be found in swarms of millions and are important pollinators for many wild species as well as crops like oilseed rape.

The nettle catkin weevil only likes the dangly green nettle flowers, where it spends most of its life mating!

Some dung beetles fly at night looking for fresh dung to feed on and to lay eggs in. Their bodies are waxy to stop the dung sticking to them and the best place to find these in your garden is on a wall near an outside light. If you're lucky you might also find their cousin the brown chafer. Adult chafers feed on leaves, buds and flowers of deciduous trees and shrubs, while their grubs live underground feeding on grass roots.

Unlike most ladybirds, the yellow and black 22-spot eats mould and mildew.

These tiny beetles measure less than two millimetres and are found pretty much anywhere that's damp and mouldy ie moss, compost heaps and leaf litter. They are among our commonest beetles and easy to find.