18 May 2011

More records of rare insects

In recent weeks friends like Dave Monk and Colin Boyd have taken some stunning photos of hitherto unrecorded, and often very scarce, insects in Brede High Wood.

In bluebell time Dave Monk photographed a little moth called the bluebell conch (Hysterophora maculosana).

H. maculosana DSCN65~3a

The caterpillars of this species feed on seeds of bluebell and, whilst it may be widespread where bluebells are abundant, it has rarely been recorded in Sussex.  It is, I think, a good example of the balance of nature.  Although there may be apparently inexhaustible supplies of its food plant (from the moth's perspective), it does not appear to have any significant impact on bluebell populations: it simply takes a modest helping of the available bounty.  Pity Homo sapiens doesn't do the same.

The picture above, by the way, is the only one I can find with the moth on a bluebell.

Colin Boyd has been making many hoverfly discoveries.  The picture below is one of his of the hive bee mimic Criorhina asilica.

P1080982 Criorhina asilica BHW

The larvae of this species develop in rotten wood with a preference for ancient woodland sites and this highlights the importance, enshrined in Woodland Trust policy, of conserving dead wood as well as living trees.

The photo below, by Dave Monk, is of an ant beetle or checkered beetle (Thanasimus formicarius)


This is a predatory species also associated with dead and dying trees, both coniferous and broadleaved.  The adults prey on the adults of bark beetles (Scolytidae) while the larvae eat the larvae of the bark beetles.

In Sussex the species has been recorded mainly from ancient parks and woods in the west but also from Eridge Old Park in East Sussex.

The adult beetles have a marked resemblance to the large velvet ant (Mutilla europaea) - Google it and you will see what I mean - a species with a formidable sting and therefore one might hypothesise that the colour and pattern is a protective device in the beetle.  However, the velvet ant seems to be so rare, nowadays at least, that any would be predator is unlikely to be familiar with its appearance  (Mutilla has never been recorded from our part of East Sussex so far as I know).  Perhaps the pattern on the beetle activates some atavistic repulsion mechanism in the brain of the insectivore.

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