Invertebrate survey at Gunpowder Park, the former Royal Ordnance Site in the Lee Valley
Sarcophagidae Macronychia polyodon RDB3, Essex Red Data species
The species was collected in Area D. It is a small fly, whose larvae develop in the nests of a range
of aculeates including sphecid wasps in the genera Crossocerus and Ectemnius and the bumblebee
Bombus terrestris.
Sarcophagidae Macronychia striginervis Notable/N, Essex Red Data species
The species was recorded in Area C. It is a parasitic fly, mainly recorded from southern England,
but also Carmarthen in Wales and Yorks. The larvae develop in the nest burrows of wood boring
Sphecid wasps.
Sciomyzidae Colobaea punctata Notable/N, Essex Red Data species
Colobaea punctata was found in Area D. There are scattered records in England and Wales, but it is
a scarce species mainly recorded from East Anglia and Kent, with scattered Essex records. Adults
are usually found beside drying out ponds and ditches, especially on levels marshes. Pupae have
been found in shells of Lymnaea peregra, Planorbis corneus and P. planorbis.
Sciomyzidae Pherbellia schoenherri Local, Essex Red Data species
This small snail-killing fly with prominently spotted wings was found in Area D. The species is
widely distributed and not uncommon, but never numerous. There are only two other Essex records.
Adults are found in the marginal vegetation of ponds and ditches, especially in fens and levels
marshes. Eggs are laid ion the shells of Succinea sp. and the larvae develop as specialised internal
parasitoids. Only one larvae can complete development in each host.
Sciomyzidae Pteromicra angustipennis Local NCR
The species was recorded in Area D, the first Essex record. It is a local snail-killing fly found in
marshes and near ponds. In the lab. the larvae will attack a wide variety of aquatic snails, each
requiring 2-3 snails to complete its development.
Stratiomyidae Nemotelus nigrinus Local, Essex Red Data species
The species was found in Areas C and D. At one time this was regarded as a scarce species, but it
has now become apparent that it is a relatively common species in a number of districts in southern
England, the East Midlands and on the coastal belt of Wales. It is scarce in Essex, otherwise recorded
from Danbury, Hatfield Forest, St. Osyth and the Ingrebourne Valley. The species is mainly associated
with fens and marshy ground in chalk and limestone districts, but also occurs locally along ditch
systems of coastal marshes, and has been found around pools in the slacks of calcareous dunes. The
larvae are probably found in shallow water or along water margins, but they may be amphibious
and to be found in moist fen litter and soil (Stubbs & Drake 2001).
Stratiomyidae Oxycera rara Local, Essex Red Data species
The species was collected in Area D. It is fairly widespread in southern and midland England,
scarcely extending further north before being replace by O. dives. In Essex there are probably
small localised populations, and it has been recorded from Barking Levels (now almost completely
lost to development), Danbury, South Stifford, Walthamstow Marshes and Sandon. The larvae
have been found in moss and on mud in open seepages associated with springs, and on wet mud at
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Essex Naturalist (New Series) 21 (2004)