Monday, June 29, 2009

Amazing beetles

My tower of logs at the end of the garden is producing some wonderful insects in this warm weather.

Yesterday there were several rhinoceros beetles (Sinodendron cylindricum) and the rare 'ancient woodland' species Tillus elongatus.

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Tillus larvae prey on woodworm larvae and other smaller beetles.  They are supposed to be largely nocturnal and therefore rarely seen (except in traps like my log tower).  All our current Sussex records appear to be from the western half of the macrocounty .  Only the females have this red and bluish black colouring: the similarly shaped males are wholly black.  Charles Darwin, no less, wondered about this sexual dimension where the female is markedly more showy than the male, but did not appear to reach any conclusion.

I wonder if that is a somewhat anthropocentric speculation.  The brighter colours in the female could be simply to do with some chemical manifestations that happen to show up in these colours and do not signify that one sex is trying to use them to catch the eye of the other.

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