The flies (Diptera) of Epping Forest
compartments. The larva lives in bracket fungi.
Xylomya maculata (Meigen)
Some flies bear a general resemblance to wasps and this species is strikingly black and yellow
marked (Plate 9). It is very rare, being known from only three sites in Britain since 1960. One was an
unlocalised record from Epping Forest in 1975 and it was therefore particularly gratifying to see an
adult caught by Roy Crossley in June 2000. The larva is found more frequently than the adult, in
dead wood and rot-holes in trees.
Euthyneura albipennis (Zetterstedt)
British woodlands are rich in dance-flies (Hybotidae and Empididae), in which some species form
dancing swarms under trees or over water. E. albipennis is a tiny species which docs not form
swarms, but has been swept from flowers of hawthorn. The adult fly, despite its small size of 2mm,
is predatory. The larva is probably also predatory and lives in rotten wood. The species was previously
known only from Windsor Forest.
Callicera aurata (Rossi)
C. aurata is one of our most beautiful hoverflies (Syrphidae), a large, deep metallic green species
with long antennae. It is found rarely with about 17 known sites since 1960. One specimen was
caught in a Malaise nap in the Forest and another just outside the boundary of the Forest. The larva
lives in rot-holes in beech.
Pocota personata (Harris)
Some hoverflies are excellent mimics of bees and wasps, and P. personata is one of the best bumble
bee mimics (Plate 9 inset). In fact, the advice I was given was to catch anything beelike flying
around standing dead wood and you may catch P. personata. This advice was followed in May 2000
and a female specimen was caught flying around a damaged beech trunk, the first record since 1947.
The larva lives in rot-holes in trees, particularly beeches.
Selected species - the hit list!
These species have not been recorded recently and will be especially targetted in future surveys.
Orthopodomyia pulcripalpis (Rondani)
This is a mosquito; most people are pleased to think of mosquitoes in decline but this species is
thought to feed on birds, not man (Snow 1990). It is elusive and very rarely recorded, with 4 site
records since 1960. The larvae live in water filled rot-holes in trees and have one distinctive feature
- they are pink! Any such mosquito larva found in rot-holes should be taken alive to a specialist,
because the species is more likely to be found by chance than by an organised survey.
Asilus crabroniformis Linnaeus
A. crabroniformis is a large robber fly (Asilidae), rather homet-like in appearance, which is usually
recorded sitting on cow dung. The adult is predatory and the larva probably associated with dung
beetle larvae. The only Epping record is an old one by Cyril Hammond and the species has not been
Essex Naturalist (New Series) 17 (2000)
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