Saturday, 21 April 2007

BEETLE-MANIA

Success on Friday 20th with finding the rare oil beetle on the Strood seawall in the early afternoon. This is the large female which was walking along the path in front of me and in previous years one or two sadly have been accidently trampled on. The beetle is only found in a handful of other sites in Essex and has a very complicated life-cycle.

It emerges on the first sunny days of spring usually early April and after mating the female excavates a hole to lay up to 4000 tiny orange-coloured eggs. Last year in mid May I found eight clusters of the newly hatched grubs coating the tops of some upright leaves. Ideally they should have been on flowers waiting for a passing tawny mining bee, onto which they must hitch a ride back to the bee's hole where it becomes parasitic on the young bee grub.
It has to be the right type of bee and there has to be a young bee grub in the hole if the beetle grub is to survive. No wonder so many beetle eggs are produced by the female in the first place.
The beetle gets its name from an oily substance which it produces if threatened.

The spring tide covering the Strood causeway onto the Island kept traffic queuing up at either end with no traffic passing for about half an hour as the water appeared to be over a foot deep. Even the bus driver got out to stretch his legs and "white van man" and several "Chelsea tractors" opted not to risk driving through.
The picture below is taken nearly at the same spot as an earlier photo taken at low tide on 9th April - see the earlier posting for comparison.

The tide did a good job in covering all the saltmarsh and apart from the black-headed gulls, the only waders around were on the drier and higher ground on Ray Island. Thirty curlew, a few redshank and one or two oystercatchers were seen.

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