A SURVEY OF THE SYRPHIDAE (HOVER-FLIES) OF REDGRAVE AND SOUTH LOPHAM FENS (Carried out during 1966 under the auspices of the Redgrave Fen Advisory Committee) W . S. GEORGE
As the fens are nearly forty miles from my home, it was not possible to make as many visits to the area as I would have liked. I had been there only twice previously, and on each occasion the weather had been unkind for hover-flies. But I was able to obtain details of a visit in 1962 by the Norfolk and Norwich Naturalists' Society, noting the hover-flies then listed by Mr. K. C. Durrant of East Dereham. It happens that no hover-flies were seen on these three occasions that I was not able to confirm during 1966; however, I list them below. IITH JUNE, 1962. (With my wife) I took Rhingia campestris $ on "Source Ridge". Little Fen, then at the north-east corner of Middle Fen took Melanostoma mellinum $ and Platychirus peltatus $ (melanic). 16TH SEPTEMBER, 1962. Mr. K. C. Durrant recorded Syrphus balteatus, S. ribesii and Ferdinandea (Chrysochlamys) cuprea. 29TH MAY, 1965. (With a Suffolk Naturalists' Society party) I was able to find only Melanostoma scalare And so to 1966. 13TH MAY. (Alone) arrived at Waveney Source 6 p.m., but despite reasonable sunshine and a walk along the entire Redgrave Fen bank of the river, I could not find any hover-flies at all. Evidently evening visits at this early season would be a failure, s<I re-visited the fens on 15TH MAY. With my brother-in-law John Westrup I walked, about midday, from Waveney Source along Redgrave bank to the sluice near grid-post R46, then back through woodland in Redgrave Far East, returning to river-bank near R64. We deviated towards L02 before returning to Waveney Source, then drove to the north-east corner of Middle Fen, where we found hover-flies rather more plentiful. The most interesting find was one male and one female of Sphaerophoria rueppellii (male being var. nitidicollis) on the river-bank of Redgrave West. This species was new to me.
We also found (onvarious parts of the reserve) Melanostomascalare* (asterisk denotes many individuals seen), M. mellinum Syrphus eligans (J1, S. albostriatus 21, Platychirus manicatus <J2, Rhingia campestris 3, Neoascia spp.* (both N. podagrica and N. dispar present), Chilosia albitarsis Q*, C. paganus (J 1 ? 1 , C. impresso C. bergenstammi rj1, C. fraterna (J1, C. honesta (Fifteen species recorded) 27TH MAY. With other members of the Redgrave Fen Advisory Committe, in evening a brief search on either side of the Middle/ Great Drain produced Pyrohaena granditarsa Q M e l a n o s t o m a mellinum rj1, Sphaerophoria menthastri (J1, Tropidia scita 1.) (Four species recorded)
5TH J U N E . I spent the afternoon visiting much the same places as on 15th May. Found: Chrysotoxum cautum Melanostoma scalare $3, Sphaerophoria menthastri r?*2*, Platychirus peltatus*, P. albimanus $2, P. manicatus (J1, P. scutatus cJ'2 (melanic) 1 , Chilosia paganus c?1?1, C. impresso rj1?1, Volucella bombylans (J1, Myiatropa florea (J1, Helophilus pendulus r?', Leucozona lucorumTropidia scita *, Syritta pipiens $2. (Fifteen species recorded)
19TH JUNE. I had a very profitable visit, with Donald Wilson spending the morning first on the rough meadow bordering the north of Middle Fen, then on Redgrave bank of Waveney from Source to R64 and back, giving extra attention to Little Fen/ Source area on return, as before found the fen-centre less rewarding. The best catch was Microdon devius, a Single specimen discovered at rest on a bush near the Source, in Little Fen, a species new to me. Other Syrphidae seen were: Baccha elongata 91, Melanostoma mellinum M. scalare Platychirus manicatus P. fulviventris 91, P. scutatus J1, Leucozona lucorum Syrphus balteatus *, S. vitripennis *, S. ribesii S. laternarius S. guttatus S. grossulariae 91, S. compositarum *, Sphaerophoria menthastri 2 1 . Parapenium flavitarsis (J1, Pipiza austriaca 91, Chilosia impresso O2?1, C. illustrata r?1, Volucella bombylans *, V. pellucens *, Eristalis tenax ยง', E. pertinax E. arbustorum cJ1?1, E. horticola cj1, Helophilus pendulus *, Myiatropa florea *, Syritta pipiens *, Tropidia scita *. (Thirty species recorded) I thought I saw Helophilus frutetorum and Sericomyia silentis, but am not certain of these two flies which "got away".
402 Transactions of the Suffolk Naturalists',
Vol. 13, Part 6
2 9 T H JUNE. In evening in fitful sunshine with Donald Wilson I collected along the entire rough-meadow margin of the north of Middle Fen. We found as feared, that fewer hover-flies were about after 6 p.m. than during the day. However, we saw: Pyrophaena granditarsa 91, Sphaerophoria menthastri Platychirus fulviventris P. clypeatus c?1?5, P. angustatus rf1, Syrphus vitripennis S. balteatus Syritta pipiens Tropidia scita *. (This last species, at any rate, was extremely abundant.) (Nine species recorded)
4TH AUGUST. In good weather Donald Wilson and I collected mainly along the north margin of Middle Fen, then around Waveney Source. We found: Baccha obscuripennis Pyrophaena granditarsa 2, Platychirus scutatus (J1, P. albimanus o P . clypeatus *, Melanostoma scalare *, M. mellinum *, Sphaerophoria scripta rj*$2, S. menthastri Q * $ * , Leucozona lucorum 2, Syrphus balteatus *, S. vitripennis *, 5. ribesii $2, S. corollae c?*$*, Chrysotoxum verralli Ferdinandea cuprea Neoascia podagrica Chilosia impresso *, C. scutellata c?2$2 (a new species to me), Eristalis sepulchralis E. intricarius (J1, E. tenax *, E. pertinax *, E. nemorum E. arbustorum *, E. horticola ยง', Helophiluspendulus *, H. hybridus 91, Syritta pipiens *, Tropidia scita 1, Eumerus strigatus *. (Thirty-one species recorded) 1 8TH SEPTEMBER. The weather being mild but not sunny, I again collected with Donald Wilson along north edge of Middle Fen, and around Waveney Source. We found: Platychirus peltatus c?1?2, P. scutatus cJ1?*, P. albimanus รถ1?1, P. angustatus , Melanostoma scalare c?1?*, M. mellinum cJ1, Leucozona lucorum 2 l (an unusually late date for this species), Syrphus balteatus *, Rhingia campestris d2, Neoascia podagrica Eristalis tenax c?*?#, E. arbustorum c Helophilus pendulus S* i* (commonest Syrphid today, many were visiting scabious flowers), Xylota segnis (J1, Syritta pipiens *. (Fifteen species recorded) Summary I am able to record fifty-nine of the 234 known British species of Syrphidae from the Redgrave and South Lopham Fens. For comparison, I have in my collection around 110 to 120 species, mostly taken in East Suffolk. Clearly there is a great deal more to find on these fens. Many common species (such as Syrphus luniger), typical fens species (such as Helophilus lineatus), or marsh species (such as Chrysogaster species) have not been seen on oui visits, but it would greatly surprise me if they are absent. There
are many other hover-flies that I meet so infrequently at home that I could hardly expect to find them in the course of so few hours. But I was delighted to find three species new to me on this new nature reserve. I hope this is an indication that other interesting finds await us. List of Species recorded Baccha e longata Fab. „ obscuripennis Meig. Pyrophaena granditarsa Forster Platychirus manicatus Meig. „ peltatus Meig. ,, scutatus Meig. „ albimanus Fab. „ fulviventris Macqart „ clypeatus Meig. „ angustatus Zett. Melanostoma scalare Fab. „ mellinum Linn. Sphaerophoria rueppellii Wiedemann „ menthastri Linn. „ scripta Linn. Leucozona lucorum Linn. Syrphus latemarius Mueller „ vitripennis Meig. ,, ribesii Linn. ,, albostriatus Fallen „ grossulariae Meig. „ eligans Harris „ corollae Fab. ,, balteatus Degeer ,, guttatus Fallen „ compositarum Verrall Chrysotoxum cautum Harris „ verralli Collin Rhingia campestris Meig.
Ferdinandea cuprea Scopoli Neoascia podagrica Fab. „ dispar Meig. Parapenium flavitarsis Meig. Pipiza austriaca Meig. Chilosia illustrata Harris ,, impresso Loew „ paganus Meig. ,, scutellata Fallen ,, honesta Rondani ,, fraterna Meig. „ bergenstammi Becker ,, albitarsis Meig. Volucella bombylans Linn. ,, pellucens Linn. Eristalis sepulchralis Linn. „ pertinax Scopoli „ intricarius Linn. ,, tenax Linn. ,, arbustorum Linn. ,, horticola Degeer „ nemorum Linn. Myiatropa florea Linn. Helophilus pendulus Linn. „ hybridus Loew Xylota segnis Linn. Syritta pipiens Linn. Tropidia scita Harris Microdon devius Linn. Eumerus strigatus Fallen