1. THE BIOLOGY OP SOME BRITISH SPHA8h0OBRID PLIES. .k thesis submitted in part fulfillment of the degree of Doctor of Philosophy at the University' of London. by ELAINE hui'JC:Ea CICELY. Imperial College of Science and Technology, Silwood Park, Sunninghill, Ascot, Berkshire. September, 1969. 2. ABSTRACT Records of seasonal occurrence and habitat ranges of 73 species of SPh.A.AROC_,JAIDA (Diptera) were ob-tined from material collected at Silwood Park, Berkshire. Life-history data obtained in the laboratory for Leptocera caenosa, L.fungicola, L.appendiculata, L.heteroneura, L.moesta, and L.claviventris. L.pullula and L.parapusio found to be parthenogenic: unmated females producing fertile eggs which developed into an all-female generation. Immature stages of 29 species (3 - Sphaerocera, 2 - Copromyza, 24 - Leptocera) des- cribed and figured. Key to puparia of 3 British genera. New species (Species A), closely allied to L.(L.)fungicola Haliday described. Identification of 66 species from material collected in two suction traps (4ft. and 30ft. above ground), demonstrated that aerial fauna sampled by the traps, dependent upon habitats in immediate vicinity (i.e. micro-habitat complex of open grassland). Possible to make a distinction between predominantly grassland and predominantly 3. woodland species: species known to occur in beech woodland near the traps were not identified in trap material. 2bur dominant species in traps: Leptocera curvinervis, L.clunipes, L.moesta, Sphaerocera pusilla. Assessment of monthly varia- tion showed no peaks in flight activity. The ratio of male to female in the samples was about equal. 48.44 of all specimens of L.spinipennis were collect- ed in trap at 30ft., other species mainly confined to the trap at 4ft. Thirty-one species (1 - Sphaerocera; 6 - Copromyza; 24 - Leptocera) found in association with rabbit-burrows. Boiled grass deposited as a bait in the burrows over eighteen months, and puparia extracted. Predominant species bred, were Leptocera claviventris, L.bequaerti, L.palmata, Copromyza fimetaria, and L.manicata. Numbers of parasites obtained (Hymenoptera: Proctotrupoidea, Chalcidoidea and Cynipoidea). Deposition of bait in other habitats made it possible to distinguish between species attracted to the bait from outside the burrow, and species definitely associated with the rabbit burrows as a microhabitat. 4. T.113hE 07 Cc:INTENTS Page ABSTRACT 2 SBCTION I. INTAODUCTION. 7-8 SECTION II. LIM HISTORIES AND HABITAT DATA. 9-109 1. INTRODUCTION. 9 2. SPECIES LIST. 14 3. M:IT'AIALS E.MHODS 18 a. Collection Techniques. 18 b. Laboratory Breeding Methods. 21 4. TAPE HISTORY D.F.,TA AND NABITAT RECORDS. 28 5. DESCRIPTION QV A NTIJ SPECIES. 103 6. GENEKIC "D"LY TO PUPARIA. 109 SCTION III. ANA.hYSIS OP SUCTION- TRAP RECORDS. 110-137 1. INTRODUCTIO-N. 110 2. Tr,2;- TRAPS AND Tahp 112 3. AMIAL..1211NA. 114 a. Composition of the fauna. 114 b. Variation in the fauna at difZerent heights. 124 5. Page. c. Variation in the fauna throughout the year. 124 d. Variation in the sex-ratios. 126 e. Influence of the weather. 129 f. Parasitic kttack. 134 g. Teneral Flies. 135 h. Comparison of the suction-trap fauna with other collections made in the vicinity of the traps. 135 SIICTION IV. THE 3PEAEa0CEID PATMA IN BURROWS or f[41 RABBIT (ORYCTCLAGUS c'TINICUIUS L.) 138-203 1. INTRODUCTION. 138 2. T1.1 DS. 143 a. Description and Location of sites. 143 b. Description of "Bait-Trap". 144 c. Sampling Procedure. 145 d. Extraction of puparia from bait, and emergence of adult flies. 146 6. Page. 3. MTEOROLOGICAL 7, ACT01-6. 149 4. AUVIROW FkONA. 152 a. Composition of the fauna. 152 b. Seasonal variation in the numbers of the inhabitant species. 154 c. Variation in the sex-ratio. 168 d. Seasonal variation in the duration of development. 170 e. The trapping methods and species distribution. 191 f. Parasitism. 198 g. Laboratory observations on the burrow fauna. 202 SECTION V. GENTaA.L DISCUSICW. 204-208 S2CTION VI. ,1C11,i0WJA-ii.E1.2S. 209-210 Si]CTION VII. SUAAARY. 211-214 ST:;CTION VIII. 3-113ilIOGAIdY. 215-230 nC2IC-v. IX. PITLT112,12 4 - 56. 231-337 7. 30Tlui- I The Sphaeroceridae are a family of small acalypterate flies (Diptera) with 3 genera and a 10G or so species in Britain. Their larvae are found in a wide variety of organic debris: decaying vegetable matter (such as, compost, seaweed, rotten fungi and the refuse which collects in nests and burrows); dung and sewage; and dead animal matter. The eggs are laid in or on the material, and the adults live in close association with the larval micro-habitats. Richards (1930) gave a comprehensive account of the British species, and subsequent workers have studied the biology of certain groups of Sphaeroceridae, particularly those associated with cow-dung. There are, however, few detailed observations of the life cycles of particular species, and the immature stages (egg,-larvae and puparium) of the majority of British species have not been described. It was the aim ,of this present study to observe and record the life-histories and behaviour 8. of flies under laboratory conditions, and to describe their immature stages; to ascertain the habitat preferences of particular species, with emphasis on those collected from rabbit burrows by a method of "bait-trapping"; and, by the identification of material from suction-trap collections, to find out when particular species were in flight, and to compare, as far as possible, these aerial samples with collections made on the ground. The flies were collected in or around Silwood Park, the field station of Imperial College at Ascot in 3erkshire. The park comprises a 300- acre estate with a variety of habitat situations, including deciduous woodland, rough and mown grass- land, arable land, and a lake and marsh (igure 53). Other collections were made in the vicinity of the conifer plantations at 'fiindsor Great Park, and at badger sets near :?okingham (Berkshire) and at Somerton (Oxfordshire). 9. II LIFE IIITORI,,JS AND HABITAT DATA 1. I).-TO'DUCTIOTT Sphaeroceridae occur in a wide variety of habitats. Richards (1930) has dealt with the habits of the British species, and has given an extensive bibliography concerning the family from all aspects. In this review it is my policy to refer only to those papers published after 1930, except when the content of earlier publications has some definite significance. The literature has been grouped into the following broad categories according' to the habitats from which the flies have been collected or reared. a. ]Vests, burrows and caves (See also Section IV): falcoz (1915) from mole nest (Talpa europaea). Richards (1932a) from wasp's nest. Richards (1950 and 1965) in association with Doryline Ants. NcAtee (1926) from starling's nest. b. Vungi: Tiuther (1946); Smith (1955a, 1956); Austin and Jary (1934); Austin (1937); Vanschuyt- broeck (1942); .-,3uxt!nl (1954) from myxomycete! 10. 0. Seawced: 3acklund (1945)*; (1960 and 1965)*; 7Harrison (1953); Thornley (1930). d. Dung and excrement: Altheir (1938); Coffey (1966)*; Fredeen and Taylor (1964)* ; Hafez (1939a and b, 1947, 1949)*; Hammer (1941)*; Howard (1900); .H.ussey (1957)*; Laurence (1953, 1954, 1955)* ; lions (1943)*; Thomsen and Hammer (1936)*; Wilson and Stoll (1929)*. e. T)ead animals: ftlapman and Sankey (1955); Deeming and Knutson (1966); Harmenter (1952a). Other miscellaneous habitat records are supplied in Harrison (1959); Leclercq (1946b); Lindner (1920); Farmenter (1952a and b, 1954a); Hichards (1944)*; }?.icrds and Ferford (1930)*; and Sabrosky (1958). Aeshovski (1967) and Vanschuytbroeck (1943b) have each given a list of biotopes (in ulcaria and nel6ium respectively) where Sphaeroceridae are found. (3pecific breeding records are supplied by those authors marked with an asterisk). kite history data, with descri-ntions of immature stages are recorded in Godard (1938); Deeming and Knutson (1966); Vogler (1900); Fredeen and Taylor (1964); Guibe (1939); Hammer (1939c); Laurence (1955); Austin (1937) and Avglishaw (1960). 11. The predtor/prey relations of the Sphaero- ceridae have been recorded by various workers: Richards (1930) refers to the observations of a number of authors, and records one parasite rearing. Goddard (193c) identified two ''iymenopteran- parasites bred from puparia. hammer (1941) reared two para- sitic Ichneumons from 3phaerocerid puparia. rarmenter (1954b); Parmenter and Owen (1954b) and -Lack and Owen (1955) discuss the role of the swift (4us alms if.) as a predator of liphaerocerids. The insect enemies of Aphaerocerids which have been recorded include various predatory flies and beetles. Hafez (1947 and 1949) records the effect of preda- tion on dung inhabiting species by two Empidid flies and various Histerid and Etaphylinid beetles; Hobby (1931 and 1933) collected the 4haerocerid prey from the dung fly Scatophaga stercoraria L. TJeclercq (1946a) records scaura L. and 6cato-, C pig; sterco7aria L. preying on L. appendiculata 411. and parapusilla Duda respectively. 1,.ohr (1943) recorded various beetles and parasitoid wasps preying on cattle-dung inhabiting species. Smith (1952) and Thornley (1933) noted predacious .i2mpididae feeding on Sphaerocerids. 12. Ilichards (1930) and Goddard (1938) recorded the presence of various acarines on Sphaerocerid adults. The following authors also make reference to mites on Sphaerocerids: 'f- ughes (1959), Smith (1955), Egglishaw (1966), and Hafez (1949); although whether the mites are parasitic or phoretic in their habits remains unclear. :Hughes (1959) has stated that the mite Uroseius acuminatus has a definite phoretic relation with Sphaerocerids. Records of other parasitic relationships are given by Zwaluwenberg (1928) who removed round worm eggs of Ascaris and Necator from the abdomen of a Borborus species; and Hamer (1941) who noted the presence of a para- sitic fungus on L. lugubris. The information discused here is based on the continuous collection of adult Sphaerocerids from a variety of habitats in Silwood Park from April 1966 until :December 1968 and collections made with suction traps from 1961 - 1965 (See Section HI).