Records of Scuttle Flies (Phoridae) from Flatford Mill, including two species new to Britain

RECORDS OF SCUTTLE FLIES (DIPTERA: PHORIDAE) FROM FLATFORD MILL, INCLUDING TWO SPECIES NEW TO BRITAIN R . H . L. DISNEY

While conducting a course at Fiatford Mill Field Centre during the week 12-19 August 1981 I took the opportunity to collect scuttle flies (Phoridae) from the immediate environs of the Centre. The sites sampled included the gardens, the old paddock and the banks of the River Stour on the Suffolk side. They are all in the 10km Square 62/03 of the National Grid.

52 species were collected in the week, including two species new to science (Disney, 1984) and a further six species new to the British List (Disney, 1982, 1983c, 1984, and below). The total represents about Vfe of the List of Phoridae recorded from Britain. Further collecting would be likely to double, or even triple, this list for Fiatford Mill. Paramenter (1965) recorded 10 species of Phoridae from Fiatford Mill, of which 6 were not collected on my brief visit.

Certainly the results of my one week's sampling suggest the immediate environs of Fiatford Mill possess an unusually rieh entomological fauna.

Recognition of species of Phoridae has been bedevilled by a troublesome and scattered literature that has tended to impede study of these ecologically interesting flies. However the family is introduced, and species other than the giant genus Megaselia are now keyed, in a recent Handbook (Disney, 1983a).

A second volume covering the 200 or so Megaselia species is in preparation.

To further the latter two additional species for the British List are reported below, along with some newly-recognised synonyms.

Species Recorded The species are listed alphabetically and nomenclature follows Disney (1983a) for the non-Megaselia species and Kloet & Hincks (1976) for Megaselia, except where indicated.

Borophaga incrassata (Meigen) - several; Conicera dauci (Meigen) common, including 31 males and 3 females visiting flowers of Hogweed (Heracleum sphondylium L.); C. floricola Schmitz - several; C. schnittmanni Schmitz - several; C. similis (Haliday) - one male; C. tibialis - one male; Diplonevra funebris (Meigen) - common; D. nitidula (Meigen) - several; D. pilosella Schmitz - common; Megaselia aculeata (Schmitz) - one male, as reported when adding this species to the British List (Disney, 1983c); M. aequalis (Wood) - several; M. afflnis (Wood) - several; M. albicaudata (Wood) - two males; M. altifrons (Wood) - one male; M. basispinata (Lundbeck) - one male; M. berndseni (Schmitz) - one male and one female the species has been known under two names in the past (see below); M. brevicostalis (Wood) - common; M. eiliata (Zetterstedt) - several; M. clemonsi Disney (1984) - one male which is a paratype; M. drakei Disney (1984) - one male which is a paratype; M. errata (Wood) - two males; M. flava (Fallen) - several; M. frameata Schmitz - several - the species has Trans. Suffolk Nat. Soc. 21

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Suffolk Natural History, Vol. 21 been known under three names in the past (see below); M. giraudii (Egger) several; M. halterata (Wood) - one male; M. hirsuta (Wood) - one male there has been much confusion over recognition of this species in the past (see below); M. insons (Lundbeck) - one male, as reported when adding this species to the British List (Disney, 1983c); M. latior Schmitz - two males the species has only recently been added to the British List after being long confused with another species (Disney, 1984); M. latipalpis (Schmitz) - one male, which represents, along with specimens from elsewhere, an addition to the British List (see below); M. longipalpis (Wood)-one male; M. lucifron (Schmitz) - several; M. lutescens (Wood) - one male; M. manicata (Wood common; M. nigra (Meigen) - one male; M. paludosa (Wood) - common; M. pleuralis (Wood) - common; M. perdistans (Schmitz) - three males an two females, which represent thefirstBritish records for this species (see below); M. propinqua (Wood)-common; M. pulicaria (Fallen)-common; M. pumila (Meigen) - several; M. rufipes (Meigen) - several; M. serrat (Wood) - a male, which represents the second authenticated British record (Disney, 1983d); M. sinuata Schmitz - several - the recognition of this species has caused much confusion in the past, but is now clarified (Disney, 1983b); M. spinicincta (Wood) - one male; M. stigmatica (Schmitz) - seve - the species was added to the British List (Disney, 1977) since the published List (Kloet & Hincks, 1976); M. subfuscipes Schmitz-several; M. sulphu ipes (Meigen) - one male - this species has been known under two names in the past (see below); M. vestita (Wood) - common; Metopina oligoneu (Mik) - common; Metopina ulrichi Disney, one female; Phora atra (Meigen - common; Phora bullata Schmitz - one male, which was thefirstBritish record (Disney, 1982) - I have since identified a male from Chippenham Fen N. N. R. Cambs, collected 28 August 1982 by Dr Ian McLean; and Triphleba nudipalpis (Becker) - several.

Taxonomic notes The following notes establish four new synonyms and clarify, or justify, certain identifications. Under each species only literature citations in the text are listed at the end. The primary taxonomic citations are all listed in Borgmeier (1968).

Megaselia berndseni (Schmitz, 1919) pygmaeoides (Lundbeck, 1921) Syn. nov. rieli Schmitz, 1937 I have re-mounted the holotype of M. pygmaeoides and compared it with slide-mounts of parts of the type material of M. berndseni. I have also examined material of M. rieli from the Schmitz collection. It is clear that a Single species is represented by this material. It follows that M. pygmaeoides must henceforth be treated as a synonym of M. berndseni.

Megaselia frameata Schmitz, 1927. imberbis Schmitz, 1934. Syn. nov. buxtoni Colyer, 1954. Syn. nov. fungivora (Wood, 1912) nec (Wood, 1909) Trans. Suffolk Nat. Soc. 21

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Colyer (1954), when describing M. buxtoni, discusses the supposed differences between it, M. imberbis and M. frameata. M. imberbis was distinguished by larger antennae and a prominent patch of sensory scales on the external face of each palp. M. frameata was distinguished from M. buxtoni by the more anterior position of the bristle on the right side of the male epandrium.

I have examined a series of specimens of this 'complex' including a reared series attributed to M. buxtoni (Disney & Evans, 1982). It turns out that the characters cited by Colyer all vary, and they vary independently. Furthermore comparison of the holotypes of M. imberbis and M. frameata reveals no significant difference. Likewise my series of M. buxtoni, previously compared with the type material of M. buxtoni, cannot be distinguished by any character common to the series as a whole. I conclude M. frameata is a species that is somewhat variable with regard to the characters cited by Colyer; and that henceforth M. imberbis and M. buxtoni must be treated as synonyms of M. frameata.

Megaselia hirsuta (Wood, 1910) atrimana (Wood, 1910) egregia (Lundbeck, 1922) hastata (Schmitz, 1922) This species varies in the degree of development of the anterior hairs/ bristles on the scutellum, the costal index and the costal ratios. The first two of these characters in particular are critical in deciding which Group of Megaselia should include M. hirsuta. I have found that different specimens will key out to G r o u p I, II or III in Schmitz's keys (1956, 1957, 1958).

However he does not allow for this species falling into Group II (where it will run to couplet 22 or 32). In Group III Schmitz keys out this species at couplet 26.1 have specimens that will key out to couplet 20 or 24. When a specimen runs to couplet 24 it is indistinguishable (on the characters given in the key) from M. pectoralis (Wood). Schmitz & Delage (1981) amended couplet 24 to accommodate M. krizelji Delage, but still omitted to consider M. hirsuta.

I have remounted three cotypes of M. hirsuta and designated a male specimen as the lectotype. It is evident that males of M. pectoralis and M. hirsuta can be readily separated by the hairs below the anal tube on the posterior border of the epandrium. In M. hirusta there is a Single hair each side. In M. pectoralis there is a Cluster of hairs each side. I suspect that M. krizelji will prove to be a variant of M. hirsuta, but I have been unable to examine a male attributed to the former species.

Megaselia latipalpis (Schmitz, 1921) The single male from Fiatford Mill, along with two males collected by D . M . Unwin in Hayley W o o d , Cambridgeshire (in May and June 1980) and a male collected b y D r A . G. Irwin at Hartford, Huntingdon, (in June 1977), represent the first British records for this species. It is keyed by Lundbeck (1922). However in Britain it has been confused with the closely related M. longipalpis (Wood), due to the costal cilia being on the borderline between 'short' and 'long'. The hind tibia is distinctive in M. latipalpis, as

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detailed in L u n d b e c k ' s key. T h e species has previously been recorded from Austria, G e r m a n y and France.

Megaseliaperdistans (Schmitz, 1924) T h e specimens from Fiatford Mill represent the first British records for this species. Their identity has been confirmed by comparison with a male f r o m the Schmitz collection. In the keys of Lundbeck (1922) this species runs to couplet 36 of G r o u p VII. It differs f r o m M. albicaudata by the entirely dark epandrium of the male hypopygium and by the upper supra-antennal bristles being clearly wider apart than the pre-ocellar bristles. The species has previously been recorded f r o m G e r m a n y , the Netherlands, Poland, Spain and Hungary.

Megaselia sulphuripes (Meigen, 1830) minutissima ( W o o d , 1910) nec (Brues, 1905) ledburiensis (Brues, 1915) fuscohalterata (Schmitz, 1919) xanthogastra Schmitz, 1940. syn. nov.

T h e colour of the halteres in this species vary from yellow to nearly black.

This has caused much confusion. I have compared the male hypopygia of a dark haltered M. xanthogastra from the Schmitz collection with typical yellow-haltered specimens of M. sulphuripes. They are indistinguishable.

F u r t h e r m o r e Schmitz evidently led himself into believing that there was a difference in the costal ratios for the two 'species' by an erroneous measurement. On the label of one of his specimens f r o m Valkenburg, Holland, he records his determination of the costal ratios as ' 8 ^ : 3 : 2 ' ( = 4-25:1-5:1). My m e a s u r e m e n t s for the same specimen are 3-36:1-24:1). However the measure f r o m the basal bristle to vein 1 is 4-24. Evidently he inadvertently measured section I from the basal bristle instead of the humeral cross vein.

I have no hesitation in establishing M. xanthogastra as a synonym of M. sulphuripes.

Acknowledgements I am grateful to F. J. Bingley for inviting me to run a course at Fiatford Mill Field C e n t r e . I am grateful to the following for allowing me to r e m o u n t critical specimens in their cares: B. H . Cogan (British Museum - Natural History), D r L. Lyneborg (Zoologisk M u s e u m , Copenhagen, D e n m a r k ) and D r H . Ulrich (Zoologisches Forschungsinstitut und Museum Alexander Koenig, B o n n , G e r m a n y ) . I am grateful to the Shell International Petroleum Co. Ltd. for a grant to aid my studies of Phoridae.

References Borgmeier, T. (1968). A catalogue of the Phoridae of the world (Diptera).

Studia Ent. 11,1.

Colyer, C. N . (1954). A new species of Megaselia (Dipt., Phoridae) from Britain; notes on fungicolous Phoridae. Entomologist's mon. Mag. 89,

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Disney, R. H. L. (1977). A curious scuttlefly(Dipt., Phoridae) new to Britain. Entomologist's mon. Mag. 112, 173(1976).

Disney, R. H. L. (1982). A species of Phora (Diptera, Phoridae) new to the British List. Entomologist's Gaz. 33, 257.

Disney, R. H. L. (1983a) Scuttleflies-Diptera,Phoridae (except Megaselia) Handbk Ident. Br. Insects. 10(6).

Disney, R. H. L. (1983b). A useful new character in the giant genus Megaselia (Diptera, Phoridae) with two new species from Britain. Z. ang.

Zool. 70, 225.

Disney, R. H. L. (1983c). Four species of Megaselia (Diptera, Phoridae) new to Britain from Hayley Wood, Cambridgeshire. Entomologist's Ree. J. Var. 95,181.

Disney, R. H. L. (1983d). A new species of Megaselia (Dipt., Phoridae) from England. Entomologist''s mon. Mag. 119, 241.

Disney, R. H. L. (1984). Six species of Megaselia (Diptera, Phoridae) from Northern England, new to Britain, and including two new to science.

Naturalist, Hull. 109,11.

Disney, R. H. L. and Evans, R. E. (1982). Records of Phoridae (Diptera) reared from fungi. Entomologist''s Ree. J. Var. 94,104.

Kloet, G. S. & Hincks, W. D. (1976). A check list of British Insects (second edition). Diptera and Siphonaptera. Hanbk. Ident. Br. Insects. 11(5).

Lundbeck, W. (1922). Phoridae. Diptera Danica 6, 69.

Parmenter, L. (1965). Notes on the distribution of Phoridae (Diptera) in Britain. Proc. S. Lond. Ent. Nat. Hist. Soc. 1965, 35.

Schmitz, H. (1956). 33. Phoridae. In Lindner, E. (Ed.) Die Fliegen der Palaearktischen Region. Lief. 187, 369.

Schmitz, H. (1957). Ibid. Lief. 196, 417.

Schmitz, H. (1958). Ibid. Lief. 202, 465.

Schmitz, H. and Delage, A. (1981). Ibid. Lief. 325, 665.

DrR. H. L. Disney, Field Studies Council Research Fellow, University Museum of Zoology, Department of Zoology, Downing Street, Cambridge CB2 3EJ Rare Breckland Plants Our many plant recorders will be interested to know that during 1983 hitherto unknown sites were discovered for several rare Breckland species.

All were on private land. Thefindsincluded: Silene otites (L.) Wibel (Spanish Catchfly), Corynephorus canescen Beauv. (Grey Hairgrass), Bromus tectorum (L.) Nevski (Drooping Brome) and, most important of all, Scleranthus perennis L. subsp. prostratus Seil (Perennial Knawel). All were on grassy heath, with the exception of the Drooping Brome, which was on disturbed chalky sand.

Thanks are due to Mrs G. Crompton for telling us of these interesting discoveries.

E. M. Hyde.

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