Leiosoma troglodytes lives on

My old friend Adrian Fowles wrote recently from Ynys Môn after a week’s holiday (well, as a National Weevil Recorder it was a weevil hunt) on the downs and woodlands of East Kent, which included a day out together in the great swathe of woodlands at Denge near Chilham…

The Denge weevil was indeed Leiosoma troglodytes, which as far as I’m aware is the first record in Britain since 1988.

The day of the weevil find is hot and windless; the paths through the woods either unshaded or narrow and barred with waving nettles and long strands of bramble. The rides are lined with disappearing drifts of rosebay willowherb; meadow cranesbill is drooping, almost wilting, along one. An old and scarred white admiral is briefly down on the bramble. The birds are entirely silent in the midday heat.

Denge weevils 3
Meadow cranesbill

The weevil-sampling process is to find the right food plant along the way; creeping buttercup is a hot favourite of this trip with one common weevil and a very rare one associated with it; then a patch of cudweed and so on. Many weevil species live on and eat only a particular plant, so to be an entomologist you first have to be a botanist and regard any habitat as a complex mosaic of food plants.

Denge weevils 2
White admiral on bramble

Sampling is conducted by means of a small white tray held under a clump of the target plant, which is shaken vigorously so that beetles, spiders and, hopefully, weevils fall onto the white surface where a quick sift and check reveals whether any gold has been found. Entomologists need both stamina and excellent eyesight.

Amongst the lush vegetation at the edge of a grassy path through the oaks and elms, a small, dumpy weevil falls onto the tray, which later proves to be the long-lost object of the search. Identification often requires the weevil to be viewed under a binocular microscope, and sometimes genitalia to be dissected for a confirmed identification, so any worthy specimen is dropped into a small phial of alcohol for further attention…what a way to go. And so to Bonsai Bank, the home of rare orchids and butterflies, where everything is investigated by ‘white tray man’ while others rest in the cool shade.

Denge weevils 1
Rosebay willowherb

And so the day proceeds with a short walk, vigorous white tray sampling followed by checking and sorting, then another walk and so on…it is slow, peaceful, increasingly addictive and a great pleasure. But you need a good memory and constant attention focused on the ground; there is little time to dream, look up and scan the empty sky for a slow-circling hobby or displaying honey buzzard. But is is companionable and the beer in the shaded garden of the old pub in Wye is well earned in the slow afternoon that follows.

A little more information on the distribution of the very rare Leiosoma troglodytes is available here.





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