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examination, and I saw a further specimen on
the 13th August in the now dry and derelict
Shadwell Dock (about to be swallowed up by the
Docklands development — a fascinating area,
with Lotus tenuis, Picris hieracioides,
Vulpia myuros, Meadow Brown and Common Blue).
My monster insect? Not a hornet, not a wasp
nor a bee, but the giant hover fly, Volucella
zonaria, said to spend its larval stages in
wasps nests, though as a mimic it would seem
better suited to those of the hornet. Perhaps
dipterists are none too keen on tearing apart
hornets nests looking for larvae in case not
all the occupants have succumbed to the
cyanide!
The first specimen of V. zonaria I ever saw
was at PERME, north of Waltham Abbey on the
13th July, 1983, where one was seen to alight
on a blackberry flower in full sun. Perhaps
the most striking feature of this fly is the
way it suddenly alights, apparently from
nowhere and then rockets off so fast one can
hardly follow its flight. The wings are very
obvious being held at quite a wide angle to the
body when at rest, yet it's flight is virtually
silent, quite different from the noisy
hornet. The wings are somewhat opalescent,
with a yellowish tinge towards the base and a
smoky patch towards the tip, again quite
different from the hornet which, of course,
also has a pair of hind wings (if one gets that
close). V. zonaria's near cousin V.
inanis, also a wasp mimic, is distinctly
smaller and of a clearer yellow. That too has
turned up in our area, a specimen (now mounted)