Thursday, July 16, 2009

Wear and Tear




Take a close look at enough insects and other small invertebrates and it soon becomes apparent that they simply wear out quite quickly. The wing tips of the crane fly in the bottom photo are tattered, presumably from the constant battering that they receive as the insects flutters amongst the grasses. It's also lost a leg, a common cranefly affliction. By mid-summer the wing tips of many insects – especially bumblebees, show severe wear as they age, which must affect their flight efficiency and the amount of energy they need to expend just to remain airborne. Butterfly and moth wings shed their coloured scales quite rapidly as the insect ages. The wings of the 6-spot burnet moth in the middle photograph have lost so many scales that they’re partially transparent. Mishaps must account for the fact that the female wolf spider in the top photo only has five legs. Young spiders can regenerate legs provided that they can still moult, but this adult will have had its last moult, so she'll have to struggle along, carrying her egg sac, on just five...

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