Invertebrate survey at Gunpowder Park, the former Royal Ordnance Site in the Lee Valley
abdomen and leaves the host to pupate in the ground. The fly appears to favour dry grassland where
the host is predominately found (Raper & Smith 2002). Individuals have been seen nectaring on
Carrot in Wales where it was recently recorded for the first time (Howe & Woodman 2001).
Tachinidae Clytiomya continua RDB, Essex Red Data species, 2 "'and 3rd British records
The species was found in Area B. Clytiomya continua was considered doubtfully British in earlier
works and it cannot now be established whether this had any basis in fact. However its recent
occurrence in Britain has been confirmed by Plant & Smith (1997) who recorded it from Essex at
Alsa Sand Pit in N.W. Essex. The present survey found the fly on two separate occasions, swept off
Hogweed and Carrot heads, and therefore good evidence for a healthy population. In Europe this
species occurs in dry warm open countryside. It is another phasiine parasitoid of Heteroptera
(Pentatomidae), in this case the shieldbug Eurydema. Eurydema oleracea (the brassica bug) is a
local species that feeds on a wide range of Crucifers, but seems particularly associated with
Horseradish Armoracia rusticana. E. oleracea was not recorded during this survey, but its occurrence
at the site would not be unexpected. Eurydema dominulus is a Nationally Scarce species with a
strongly southern distribution not recorded from Essex, forming highly localised colonies on
Crucifers, particularly Cuckoo-flower Cardamine pratensis.
Tachinidae Freraea gagatea RDB3, Essex Red Data species/NCR
The species was found in Area C, new to Essex. It is a parasitic fly recorded from Wilts., Berks.
Suffolk and Perthshire. Its status has been revised from Vulnerable in Shirt (1987). The fly has
been recorded in heathland and grassland. The larvae are parasitoids of adult ground beetles, and
several larvae may develop in a single host.
Tachinidae Peribaea setinervis Notable/N, Essex Red Data species
The species was found in Area D, the second Essex record. It has a disjunct distribution in Southern
and Central England and Scotland. Its status has been revised from Rare in Shirt (1987). The larvae
are parasitoids of the caterpillars of Geometridae and Lasiocampidae (Lepidoptera) that feed on a
variety of trees and shrubs. Management should maintain open rides and clearings in woods, ensuring
a wide range of trees, shrubs and herbs.
Tachinidae Phasia barbifrons NCR
The species was swept off Carrot flowers and herbage in Areas B, C and D, new to Essex. Phasia
barbifrons was exhibited at the 1999 annual meeting of Dipterists Forum by Laurence Clemons
who found it at a pasture site in Kent in June 1999; it is another phasiine presumed to parasitise
Heteroptera. Its build and appearance resemble the common species P. pusilla with which it may
have been confused in the field (Clemons 2001).
Tachinidae Subclytia rotundiventris RDB3, Essex Red Data species/NCR
The species was found on two occasions in Area D, new to Essex. It has been recorded in southern and
Central England with well over a dozen post-1960 localities, with an increase in recent years and in
the New Forest area. This may only reflect an increase in recording, and this is still a highly restricted
species. It occurs in broadleaved woodland, including birch scrub in areas of wet heath and fen, heaths
and calcareous grassland. The larvae arc parasitoids of several species of shieldbug including species
associated with Birch, Juniper and Gorse such as Elasmostethus interstinctus, Elasmucha grisea, and
Piezodorus lituratus. Management should maintain open rides and clearings in woodlands, ensuring a
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Essex Naturalist (New Series) 21 (2004)