From the minuscule to the mighty, tree-dwellers to pond-swimmers, millions of beetle species reveal a wealth of information about the world we live in 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 ...