Richard Jones: Why beetles are the most important organisms on the planet
The phrase “they come
in all shapes and sizes” could have been coined just for the Coleoptera — the
beetles. At a fragile 0.325mm long, the Colombian featherwing (Scydosella
musawasensis) has a good claim to being one of the smallest
free-living insects in the world, and is tinier than many single-celled
creatures. At the other end of the spectrum, the obviously named titan beetle,
a huge Brazilian longhorn that can snap a pencil in its jaws, reaches 167mm –
about 500 times the size.
Coleoptera range from
the narrow sylph-like elegance of the mould beetle (Adistemia watsoni) crawling
up the musty wall of a museum store-room, to the burnished brass bauble of the
golden leaf beetle (Chrysolina banksi),cumbersomely crawling over the
black horehound plant it feeds on.
They occur from
seashore to mountain top. Around the south and west coasts of Britain, the tiny
pale ground beetle (Aepus robinii) survives in silt-filled cracks
in seashore rocks, and is covered up by the tide twice a day. Meanwhile the
rainbow leaf beetle (Chrysolina cerealis) is only known (in Britain
at least) from Snowdon in Wales, where its chubby larvae feed on a few clumps
of stunted thyme growing on the windswept mountainsides.
Beetles (or more often
their larvae) eat anything from wild and garden plants (too many gardeners
revile the poor old lily beetle (Lilioceris lilii), to pollen, algal
film, leaves, fruits, nuts, stems, roots, dung, carrion, rotten wood,
construction timber, harvested grain, stored food, other invertebrates, and
each other. They live in water, up trees, in the soil, in ant nests, in bee
burrows, in our homes; they visit flowers, they patrol leaves, they fly and
bump at the lighted window of a late summer evening. Platypsyllus
castoris lives in the pelts of beavers, scraping a living from dead
skin and sebaceous secretions. Beetles live everywhere and do everything… read
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