Faced with over a thousand small pots of pickled insects from pitfalls in Regent’s Park, I quickly remembered why I don’t like trapping insects. It isn’t the slightly acrid stench of decay that the industrial alcohol is valiantly attempting to restrain. Nor, indeed, is it the texture of the slugs, which take on a resilient wine-gum plasticity after six months in vodka. (The delivery of denatured ethanol had not arrived by the May launch of Mission Invertebrate, so a couple of bottles of Sainsbury’s own-brand hooch was acquired.) It is the sheer numbers of insects that have to be painstakingly sorted under the microscope.
The problem with pitfall trapping in a London park is that species diversity is hovering around the zero mark. A few common ground beetles (ubiquitous Nebria brevicornis and Pterostichus madidus dominate), rove beetles (devil’s coach-horse, Ocypus olens and some large Philonthus), black ants (Lasius niger), and several very common woodlice made up 99.9% of the catch. It was so very mundane.
In the normal course of entomological activity — the sweep net my weapon of choice — there is a subliminal sifting, by which 99.9% of the activity in the net can safely be ignored whilst they fly or crawl off; amongst them the more unusual insects can be sought. Under the stereoscope, though, every scrap of protoplasmic matter has to be shifted aside, until a nugget is revealed. And so it was with this, my rare-versus-obscure find from the haul — Parabathyscia wollastoni.
What Parabathyscia gets up to, nobody is quite sure. It has been recorded under decaying rhubarb and lettuce leaves, in rotten seed potatoes, and in a bumblebee nest. The National Biodiversity Network Atlas lists only 14 records, but the beetle has no official conservation status — the implication being that it is rarely recorded because it is so easily overlooked. It may be overlooked because it is almost certainly a subterranean insect. It is blind, completely lacking eyes. Weird.