The trouble is: we don’t actually know how many species of beetles are out there. About 400,000 species have been described in scientific books and journals, and representative specimens are housed in the world’s museums, but surveys in the tropics suggest the true total may be anywhere from three to 33 million species - and they come in a variety of shapes and sizes...
Ground beetles in the family Carabidae are familiar to all, whether running about in the sunshine across the patio, or hiding under a flowerpot or log.
They might be considered ‘typical’ beetles, with their long legs, oval elytra, narrow or heart-shaped pronotum, prominent head and slender antennae. But other beetle families have evolved a bizarre and bewildering array of body forms.
The domed, almost hemispherical spottiness of a ladybird contrasts with the flat-flanged rim of a green tortoise beetle, Cassida viridis, under which – if attacked – it can withdraw its head, legs and antennae to clamp down onto a leaf surface.
The cylindrical form of the pinhole borer, Platypus cylindrus, is ideal for tunnelling perpendicularly into thick oak bark, while the steam-rolled flatness of Hololepta plana is perfectly suited to life pressing beneath rotten bark of decaying poplar trees as it pursues the larvae of other insects in the dank fungoid layer.
At the other extreme, the glossy metallic baubles of the leaf beetles (Chrysolina and Cryptocephalus are good examples) are convex to the point of globularity. They live an exposed life feeding on leaves and flowers, so waddle in the open rather than shimmying into the undergrowth. And anyone lucky enough to find an oil beetle (Meloe) may wonder at the female’s ability to drag herself about through the grass. Her distended abdomen may contain 40,000 eggs.
Leaf beetle © Getty Images
