120 BR. J. ENT. NAT. HIST., 7: 1994 



Knowledge of the Lepidoptera is thus still at an early stage with little more than 

 100 species of moth so far recorded. Light trapping was thus arranged for several 

 field meetings in 1994 to cover different parts of the Park and further investigation 

 of the "micros" would also be welcomed. 



Diptera. On the September 1992 field meeting Ian McLean concentrated attention 

 in the vicinity of Mungell's Pond and found several species of interest, especially 

 Dolichopodidae and Sciomyzidae, which he exhibited at the 1992 annual exhibition. 

 On the same day I investigated the hedges and riverbanks for fungus feeders; I was 

 surprised to find 36 species of fungus gnats including the very local Megophtalmidia 

 crassicornis Curt, in two areas, and four species of Platypezidae. Macquartia grisea 

 (Fall.) (Tachinidae), a parasite of chrysomelid beetles, was frequent, and two other 

 species of the genus with similar habits have subsequently been found in the Park. 



The Diptera Workshop on 8. v. 93 preceded the first field meeting by a week, and 

 morning fieldwork was productive, the most surprising find being Meligramma 

 euchroma (Kowarz) (Syrphidae), which Alan Stubbs spotted on oak foliage; it is 

 decidedly uncommon with larvae feeding on tree aphids. On the 15.v meeting about 

 150 species of Diptera were recorded, including 34 species of hoverfly and 14 species 

 of cranefly. The cow parsley flowers near the river were attracting a good range of 

 species including Cheilosia vulpina (Meig.) and Parhelophilus frutetorum (F.), while 

 Ron Boyce was able to photograph P. versicolor (F.) sitting on foliage further along 

 the river. Several other Cheilosia species were about including C. honesta Rond. and 

 Epistrophe nitidicollis (Meig.) was found on oak foliage by the river. Gavin Boyd 

 recorded Xanthogramma pedissequum (Harris) near Tufty's Corner. Several of the 

 larger Tachinidae were seen including Gymnocheta viridis (Fall.) on tree trunks, 

 Tachinafera (L.) and Pelatachina tibialis (Fall.) on foliage; the scarce species Wagneria 

 gagatea R.-D. was found on both these May visits. 



On 18. ix about 125 species of Diptera were recorded, with calypterates especially 

 frequent and 1 1 species of Sciomyzidae were found; Dichetophora obliterata (F.) was 

 in numbers in the lane between the south end of the lakes and Andrew Halstead found 

 Ilione lineata (Fall.), which specializes in the freshwater bivalves, near Mungell's Pond. 

 This, with his find of Euthycera fumigata (Scop.) by Sandford Lake on the same 

 day, brought the list of "snail-killing flies" (Sciomyzidae) for the Park to 30 (45% 

 of the British species; the other 28 were exhibited by me at the 1993 Annual 

 Exhibition). A few late syrphids on this occasion included Cheilosia pagana (Meig.) 

 and C. vernalis (Fall.). 



Much fieldwork was carried out on the Diptera on 26 other dates during 1993 and 

 with the assistance of specialists in several families, most of the material has now 

 been identified, enabling 975 species to be recorded. Both higher plant and fungus 

 feeders are well represented. Among these were 1 1 currently afforded Red Data Book 

 status and a further 43 "notable" species; a range of these as well as some species 

 new to Britain were exhibited at the 1993 Annual Exhibition and are listed in the 

 Exhibition report. Only a few other species are therefore mentioned here. 



A dolichopodid Nematoproctus distendens (Meig.), which is found by woodland 

 streams in the New Forest and otherwise recorded in Britain only from one site in 

 Glos., was found in June and July around a muddy creek (Fig. 5) in Sandford Copse. 

 Eustalomyia hilaris (Fall.) (Anthomyiidae), associated with Sphecidae nesting in rotten 

 wood, was found in the carr at the south end of Mortimer's Meadow; most British 

 records are from the Thames valley. Volucella inanis (L.) (Syrphidae) was observed 

 in several areas during August. The aquatic Stratiomyidae have not been found but 

 we know that Stratiomys potamida (L.) has occurred, as it was photographed by Ron 

 Boyce on umbels near White Swan Lake on 30.vii.1985; it may have disappeared 

 during the drought years. 



