THE BIOLOGY OP SOME BRITISH Spha8h0obrid PLIES. .K Thesis

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.

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) described 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 variation 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 collected 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

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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.

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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.

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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 grassland, 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 parasitic 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 parasitic 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). Attempts to breed various species in the laboratory, have thrown light on a number of important aspects of the general biology of the Sphaeroceridae, including habitat preferences, 13.

details o±' life-histories end the morphology of the inaature staves of a number of species. 14.

2. 3rJ.3JTai MST

The following species were identified from material collected in Silwood Park (and certain other localities) Sphaerocera (;$phaerocera) curvipes S. (S.) monilis Haliday. S. (Ischiolepta) pusilla (1?allen) S. (I.) scabricula haliday. S. (Lotobia) pallidiventris (Neigen). Copyomyza (Olinea) atra (Meigen). C. (1111oborborus) flavipennis (.F_Taliday) O. (Crumomyia) nigra (Meigen). C. (Pungobia) fimetaria C. (V.) nitida (Meigen). C. (P.) roserii (Rondani) C. (Borborillus) costalis Zetterstedt. C. ().3.) nitidifrons (Duda). C. (B.) sordid; Zetterstedt. C. C3.) uncinata (Duda). C. (-3.) vitripennis (eigen). C. (Copromyza) eouina,(Pallen) C. (C.) similis (Collin). C. (C.) stercoraria (Meigen). 15.

Leptocera khtptocera) caenosa (Londani). h. (h.) curvinervis (Stenhammar). L. (i.J.) fontinalis (Fallen). L. oldenbcri (Duda) L. (ilachis-coda) bre7iceps Otenhammar) form cryptochaeta (Duda), (a.) limosa ( Follen). L.(A.) lutosa. Otenhanimar). b. (R.) varicornis (Strobl). L. (Pteremis) fenestralis (allen). L. (Pteremis) fenestralis form nivalis (Haliday). L. (3pinotarselia) humida (halidcy). L. (Opacifrons) coxata (btenhammar), L. (Chaetopodella) scatellaris (}{aliday). L. (Thoracochaeta) zosterae (Holiday). L. (Puncticorpus) cribrata (Villeneuve). L. (himosina) appendiculata (Villeneuve), L. (L.) beduaerti (Villeneuve). L. (L.) 1,pfrons (3tenhammar). L. (h.) claviventris Otrobl). L. (L.) clunipes L. CL.) collini (Richards). L. (L.) denticuleta (Duda). L. (L.) flavipes (I`':eigen). 16.

h. (It.) fungicola (Haliday). h. (h.) heteroneura L. (h.) luteilabris (Aondani). L. (L.) manicata (=,iichards). ( ).) mirabilis (Collin). h. (h.) moesta (Villeneuve). (h.) ocnrines (. rieigen). L. (h.) palmata (itichards). h. taruusio (Dahl). _L• (1..) pseudolucoptera (Duda).

L. (h.) pseudonivalis (Dahl). j-J. (Ia.) pullula (Zetterstedt). h. (L.) rufilabris (Stenhammar). h. (h.) schmitzi (.J.Xida). . (h.) secundaria (Duda). •('.) setaria (Villeneuve). (h.) silvatica (Feigen). h. 0,.) spinosa (Collin). L. (L.) talparum (Richards). ( ,.) vitripennis (Zetterstedt). L. (Trachyopella) atomus (10ndani). L. (T.) melania (Haliday). L. (iialidavina) _s_pinipennis (Haliday). 17.

(Slachisoma) aterrima (Holiday). Li. ( ) pilosa (Duda). (Coproica) acatangula (Zetterstedt). (C,) ferruginata (Ttenhammar). Ti. (C.) hirtula (Rondani). Li. (C.) lugubris (r aliday). L. (C.) pseudolugubris (-Duda).

.4: • (C.) vagans (haliday). 18.

3._EaIALS Alai D 14 12110DS

a. Collection Techniques The collection techniques employed can be subdivided under two broad headings: (i) Direct collection (ii) Indirect collection (a) Deposition of 'bait' in the habitat. (b) Collection of material from habitats. (i) Direct collection: The adult flies were collected from specific habitats by means of a "pooter" or aspirator, at the same time observations could be made on the locomotory behaviour and general habits of the flies. The flies apparently suffered no damage by being sucked into the collecting tube. In the laboratory they were anaesthet- ized by ether vapour in order to facilitate identification. (ii) Indirect collection: (a) Depiosition of "bait," such as grass cuttings (collected as lawn mowings and prepared by boiling) and rat dung (collected from laboratory animals, 19. and boiled to remove contaminants) in a number of habitats. The bait was either exposed in such a way as to attract females for egg-laying, or was retained within a trap so that the adult flies were collected. The bait was deposited in three different says: a shallow plastic dish containinc rat dung was placed in such habitats as the entrance to rabbit burrows where it was left for over a week. In the laboratory the bait was emptied into a so- called emergence jar. (The 'emergence jar' was a 21b glass jar painted black with a blackened lid, through which projected a transparent plastic tube sealed with a cork. emerging adult flies were assumed to be photo-tactic, and could be collected from the tube). Ilastic mesh cylinders (;Figure 1, described in detail in Section IV) were filled with boiled ,7,rass cuttings and placed in grass tussocks or small maznmal ruins. The bait was returned to the laboratory a::ter periods of exposure of up to four weeks, and puparia removed by a process of direct flotation (See bection 1V for details). 20.

FIGURE 1: Plastic mesh cylinder (slightly less than actual size). Used in bait-trapping experiments. 21.

=adult flies were trapped in a modified pit-fall trap with attractant bait (boiled grass cuttings) Uigure 2) of a type originally used by Basden (1955) for Drosophilidae. The trap consisted of a plastic beaker with a screw top (height, 11 cm. Greatest diameter, 7.5 cm.) through which two pieces of plastic tubing (length, 7.5 cm.) were inserted. The bait was added to a depth of 3 cm., and the whole device sunk into the soil, so that the top of the lid was level with the ground surface. These adult traps were exposed for weekly periods in a variety of habitats. on occasions when the traps were exposed for longer periods puparia and larvae were collected from the bait. (b) Collection of habitat material: Naturally occurring breeding media and general refuse such as rotten fungi, dung (badger and rabbit), compost (rotten lawn mowings), and small mammal run litter were collected in polythene baFs, and investigated in the laboratory for the presence of puparia. The puparia thus obtained were put in individual corked tubes, and placed in the darkened room of an outer insectary to await emergence. In this way the puparia of some species which. were not bred 22.

FIGURE 2: Plastic beaker with screw-top lid (actual size). Used with bait, to trap adult flies. 23. in the laboratory were determined. A number of breeding records for parasites were also obtained.

b. Laboratory Breeding Methods The ease of rearing species under laboratory conditions varied a great deal, and often several breeding media were tried. In some cases no attempts at laboratory-rearing were successful, whilst other species remained in culture continuously for up to two years. Cultures were usually started with a single wild-caught female. The female was either assumed to be fertilised, or was placed with a male of the same species in the rearing chamber. Plies were reared in a constant temperature room at 2000. with 16/24 hours light (except in certain cases where stock cultures were kept in the laboratory at room temperature). Cultures once started were easy to maintain throughout the year with no evidence of obligate diapause.

(i) i3reedin<~ 3 iedia number of diferent media ,iere used (designated here as Yypes A - 1)

Type A2 grass cuttings. These were collected as lawn mowings (or cut from grass grown in a greenhouse 24.

during the winter months), and boiled with tap water until they were thorouly softened, and any con- taminant species killed. The water was drained off, and the grass mixture was available for use. Type B: grass extract on filter paper. The decanted liquid from Type was used to moisten black filter -paper, on which the egs were laid, and where they were easily detected. (A method originally used by ilafez (1939b) with dung extract). Type C: nutrient agar with added horse serum. The agar was dissolved in distilled water, boiled and allowed to set in plastic pill boxes (height 2 cm., diameter 4.5 cm.), to a depth of about 1 cm. The pill boxes were placed in the rearin,;.- chamber. (Method originally devised by Galtshoff et al., 1959). Type B: cultivated mushrooms. The mushrooms were partially broken up and placed in the rearin chamber. Type E: in the case of one species L. humida, mud from a stream was placed with leaf litter in a rearing chamber and periodically replenished with tap water. Breeding media referred to in the text will be described as Type A etc. with no further details. 25.

(ii) :tearing- Chambers: sphaeroceridae in general are small flies with diminished powers of flight. Their wings are used in short bursts of flight activity, which may be mistaken for a jumping or hopping movement. (In the case of the larger Copromyza species this habit may be supplemented by periods of prolonged and active flight, which may account for the difficulties experienced in rearing these species in the laboratory). It was therefore assumed that the rearing chamber would not hive to enclose an area large enough to accommo- date the prolonged flight of the adults. Flies were bred in one of two rearing chambers. Stock cultures were set up in 2 lb. glass jars with cellulose-acetate lids. Type A medium was used, and several individuals were added.

.:resh- breeding, material was added periodically. These stock cultures survived for long periods over a number of generations. It appeared that so long as the sides of the jar on which the adult could walk were dry, and there was freshly boiled grass the adults continued to reproduce. The larvae fed on the decomposing material which accumulated in the bottom of the jar, and pupated on the drier 26. sides of the container. Adults could be removed by the insertion of a "pooter" through a hole in the lid of the jar; puparia were similarly removed with a paint-brush. Individual cultures were set up with media of all types. n sin le female, or a pair of flies were plced in a plastic dish (figure 3, height, 4 cm. and diameter, 16.5 cm.). A glass tube projected through a hole in the side of the container, and contained distilled water with a "wick" of cotton wool; this maintained a saturated atmosphere . The 2;rass extract of Type medium was replenished by means of a pipette inserted throuh the lateral aperture. Similarly adult flies or immature stages could be removed. 'the.; the adult flies were re- quired for identification, ether vapour was blown into tne chamber. The adults aimarently suffered no ill-effects from the use of this anaesthetic, recovered after a few minutes, and continued normal locomotory behaviour. In order to obtain the immature stages of a particular culture the whole medium (Types 0 or h) was emptied into water, and the egs and puparia removed from the surface floating fraction. The larvae were obtained from the sink- ing fraction, when the water was decanted. 27.

FIGURE 3: Plastic dish (actual size). Used as a rearing chamber in the laboratory; showing glass tube with cotton wool wick. 28.

4. I IIISTUjiY DATA KgJ) HI,BITATAhCORDS

3phaeroceridae were collected regularly from a variety of habitats in Silwood Park. In this section the data for each species have been dealt with separately. The nuibers which were caught in the suction traps (See Section III) have been listed for each species, although those which occur more than ten times in the suction trap -material have been dealt with in greater detail in Section III. The immature stages are distinctive in each of the three genera. However, within each genus, there are definite points of difference between the species, such as in length and colour, and in the shape of the anterior spiracular processes of the prothorax. In the following notes, the characteristic form of the imhiatura stages in each genus, have been dealt with in detail at the beginning of each section; and in subsequent descriptions only those points which could act as distinguishing features for each species have been mentioned. segments of the larvae and puparia 29.

nave been labelled from I to for convenience; segment I bein tie prothoracic segment, which bears the anterior spiracular processes. :A-cddard (1938) found no real F7eneric or specific differences in the cephalopharyngeal skeleton of the third instar larva as it occurs in the puparium. However, j)eeming. and Knutson (1966) ave postulated that there may be specific differences in the dep:ree of sclerotisation of this structure in Copromyza. Goddard (1936) devised a specific key to the puparia of the fourteen species which he described (which included species from all three genera). However, with the addition of new material it appears that some of the characters which he used are not entirely exclusive, and it is difficult to adapt his key to incorporate raterial which has since been described. A provisional key to the puparia of the three -J3ritish genera, based on information from a number of sources (includinrz, Goddard, 1938) has been included at the end of this section. 30.

;dotes on the species (The order in which these species are treated is adapted from that used by hichards, 1930).

Sphaerocera Latreille. One Sphaerocera puparium has been previously described and figured: S.curvipes by Goddard (1938). The general description which follows is based on features present in the puparia of four Sphaerocera species (three of which are described and figured here). All four puparia show essential similarities in shape; the main differences are in dimen- sions, and in the structure of the anterior spiracular processes. The puparia, which are black/brown and opaque, are compact elongate-cylinders, tapering at each end, with only a slight dorso-ventral com- pression at the anterior end. The anterior spiracular processes (on the prothoracic segment or segment I), which are copipact palmate structures, lying closely adpressed to the cephalic cap of the puparium, have specific differences. segmentation is distinct; se,rmients IV - XI bear rows of fine spines enclosing an additional row of "pseudopods". The posterior spiracles are not generally visible. 31.

Goddard (1936) illustrated them as small, black oval areas near the extreme posterior margin of the last sesment, They are not visible on the ventral surface, and have not been illustrated in - igures 4, 6 and The adult fly emerges from the puparium when a dorso-ventral split occurs at the posterior margin of segment III, and the whole cephalic ceo is lifted off. Only one Sphaerocera larva is figured here, that of S,pusilla (Figure 7) and none have been previously described. The third instar larva is white and translucent. It is cylindrical in shape, tapering towards the anterior end and slightly at the posterior end. The prothoracic segment (here referred to as segment'f5 has a pair of lateral palmate spiracular processes. The head of the larva bears a pair of two-segmented antennae, which are apparently borne on two anterior projections of the cephalic sement. The buccal opening is surrounded by rows of sclerotised "teeth". The main point of difference between the larva of Sphaerocera and those of Leptocera and Copromyza is in the arrangement of the locomotory spines and hooks on the antero-ventral margins of segments 32.

IV - I. In Sphaerocera There does not appear to be the row of large hooks found on each of these secments in the ocher two genera. Instead, there is a row of oval structures of varying size, which project out like pudopods in the larva, and which are clearly visible in the puparia. Any differences in function have not been investigated. Goddard (1938) figured the cephalopharyngeal skeleton of S.curvipes and found no distinct generic differences. The two Sphaerocera egs which have been previously figuredt S.curvipes (Goddard 1938; Hammer 1941) and S.pusilla (Hammer 1941) and that which is figured here, S.monilis (:.'figure 5), show great similarity in form. The eggs are white and opaque, and oval in shape with a slight flattening of the dorsal surface. The surface of the eg is interrupted by a series of longitudinal furrows or indentations, and the anterior end is slightly flattened and has a distinct split through which the larva emerges. 33.

$ubg. ..iphaerocera

1. Socurvipes. Specimens collected: numerous individuals. 2M 7P caught in suction trap at Oft. (irar B) in April, Lay, August, september and October, on eight separate occa:ions. honthly records: 2 - 12.1 habitats: on rottingfungus on fallen tree., Parasites: four puparia collected from decayed lawn mowings in a garden tip in June 1966 were parasitised by Ehaenopria spp. (Proctotrupoidea) which emerged in July and August of the same year.3 Laboratory observations: attempts to set up a regular culture on Type A. medium were unsuccessful, although the adults survived for up to 6 days.

1,The monthly records for each species are compiled from a number of sources. New records cited for the first time here are underlined. 2Only those habitats from which a species has not previously been recorded are mentioned. 3All the Hymenopteran parasites have been determined by G. .J. Nixon (Chalcidoidea and Proctotrupoidea) and J. Quinlan (Cynipoidea) of the British Museum (N.H.).

34.

2. S.monilis Specimens collected: numerous individuals 11 2? were caught in suction trap at 4ft. (Trap B) on three separate occasions in April, July and August. Monthly rec,7)rdc 2 - 4, 6 - 11. Breeding records: seven puparia collected from decayed lawn mowings, adults (4M 3?) emerged 3 - 8 days later (June). Laboratory observations: wild-caught individuals placed on Type A medium at 20°C., eggs were laid, but no reaular breeding occurred. Longevity: CS days (female). Immature stages: Puparium (Vigure black/brown. Length, 2.35 mm. Width (at segment VII) 1.0 mm. Anterior spiracular process black, extended into 3 - 5 thick blunted papillae of unequal length. Typical Sphae-rocera purarium (see previous description), white. Length, 0.9 mm. Width (at wideot ,2 mm, Tape= at both ends, which are rounded. Chorion with numerous longitudinal ridges. 35.

Subg. Ischiolepta Lioy.

3. S.pusilla Specimens collected: numerous individuals. 2291V1 (126 with thickened hind femora) 273F caught in suction t- at 3Oft. (Trap A) and 4ft. (Trap B), see Section III for details. Konthly records: 1 - 12. Habitats: on horse dung (1M Li'); on rotting fungi (Coprinus sp., Bussula ochroleuca Faxillus involutus Agaricus silvicola) in woods. Parasites: twelve parasites (Phaenopria sp.) reared from puparia collected from rotting grass cuttings in garden tip in June and August. Mites: this species is often affected by mites, and on some occasions the mites were so numerous on a newly-emerged fly that its wings were unable to expand, and it remained stunted. None of the mites have so far been identified. Breeding, records 7M (4 with thickened femora) 7F were brad from puparia collected from rotting grass cuttings. Laboratory observations: a stock culture was set up on Type A medium at 20°C. The life-cycle was 36.

complete in 21 - 24 days, and tne pupal stage lasted from 8 - 12 days. Althougil no exact figures were taken, on no occasion did an observed female

produce an F1 generation which included males of both forms (thickened or unthickened hind femora), but those females whose off-spring was identified, produced males of either one or the other form. Longevity: 43 days (male); 11 days (female). Immature stages: Puparium (Figure 6), black/brown. Length, 0.5 mm. Width (at segment VII) 0.75 mm. Anterior spiracular process, black, palmate with up to six unequal and irregular papillae. Typical Sphaerocera puparium. Third instar larva (Figure 7), white. Length, 2.6 mm. Anterior margins of segments III - XI extended into tubular "pseudopods". Posterior spiracles sessile on dorsal surface of segment XII, each spiracular plate with three radial slits (Figure 7E). The egg of S.pusilla has been figured and described by hammer (1941).

4. S.scabricula. Specimens collected: 6h 12P. 4M 4F were caught in the suction traps on eight separate occasions 37.

(3A 4j at 4ft. Trap 3; at 30ft. Trap A ) from June to October inclusive. Monthly records: 4, 6, 7, a, 9, 10. Habitats: in the deepest layers of compost (decaying lawn mowings) on a semi-liquified substrate. Parasites: seven individuals of Fhaenopria sp. were reared from puparia collected from decayed lawn-mowings in August (parasites emerged in September and October). :Breeding records: 4.JA 3P were bred from puparia collected in decayed lawn-mowings from garden tip in June - August. Laboratory observations: Attempts to set up a stock culture on Type A medium were unsuccessful. Pairs ow flies were kept in total darkness, but failed to lay egg although they survived for several weeks. Longevity: 29 days (male and female). Immature stages: ruparium. (Pigure 6), typical Sphaerocera puparium, black/brown. Length, 1.8 mm. idth (at segment VII) 0.7 mm. Anterior spiracular proceSs -('iure 80), black, sessile with up to four pale digitate papillae. On segment XII the 38.

"pseudopod6" on the ventral surface -rorm a triangle around the anus. The position of the posterior spiracles is not distinct.

Subg. Lotobia Ldoy.

5. 5.221441Ientris. Specimens collected: 2}' were caught in the suction trap at Oft. (trap i-3) on two separate occasions in August. 11onthly records: 1, 2, 5 - 7, 9, 12.

Genus Copromyza Valien.

'Pour puparia oz .loprom,,,rza have been previously described. C.r lacialis (eigen), J.ecuina and C. stercoraria by Goddard (193); C.Dedestris (1 eigen) by Deeming and Knutson (166). The followinc general description is based on information from these authors, and from fef.tures of the puparia of two a6Litional species, C.nira and C.fimetaria (figures 9 and 11). All the Coprornyza puparia which have been figured so far have remarkable similarities. 39.

They are, without exception, olden/brown and translucent, of 1g dimehsions, but of a uniform shape a compact, elongate-cylinder tapering to blunted ends. The anterior spiracular processes of the prothoracic segment are black, sessile palmate structures with 7 - 8 blunted papillae. The segmentation is distinct, and there are a series of bristles and hooks on the antero-ventral margin of - segments IV - XI. The sides of a varying number of segments between II and X may be dorso- ventrally compressed to form longitudinal foveae. Segment XII is extensively wrinkled, with the remains of the ventral anus of the larva. The posterior spiracles open at the end of short almost sessile blunted terminal projections, each spiracular plate with tnree slits. The third instar larva of Copromyza nitida was figured by .kennig (1952), and Guibe (1939) described the larval staes of C.pedestris. Laurence (1955) figured the anterior or prothoracic spiracles of the larvae of C.nitida and C.hirtipes, and the posterior spiracles which he found to be characteristic of the genus Copromyza. 40.

two main features which would appear to distinguish the larvae of Copromvza are the form of the posterior spiracular processes on segment XII, and the series of locomotory spines on the antero- ventral margins of segments IV - XI. The posterior spiracular processes are very blunted, hardly projecting from the surface of the last segment, and with none of the tufts of bristles which are so characteristic of Ieptocera larvae (C.fimetaria: Figure 1C). Each patch of sclerotised outgrowths on segments IV - CI consists of several rows of spines, with a median row of larger hooks. This is best illustrated in the pupariura of C.fimetariat Figure 3. This situation ocmirs in heptocera, but in Sphaerocera the hooks are replaced by a series of oval-shaped structures, whose exact role has not been investigated. The egzs of jopromyza hirtipes and C.equina were figured and described by -hammier (1941).

Subg. Olinea Richards.

6. C.atra Specimens collected: 8M 6F (one pair taken in copula 41.

in August) 21M 15P were caught in the suction trap at 4ft. (Trap 13), 11:i was caught at 30ft. (Trap A). 1Lonthly records: 1 - 12. Habitats: on pile of grass cuttings.

Subg. Alloborborus Duda

7. C.flavipennis. Specimens collected: 1M 1l was caught in suction trap at 4ft. ci2rap on 24.4.61. ilonthly records: 2 - 6, b, 9, 10, 11. ',Elbitat! under heather.

Subg. Crurnomyia Ilacquart.

8. C.nigra No specimens were caught directly. Breeding records! 12M 11F were bred from boiled grass bait deposited in several rabbit burrows during December/January 1969. he first adult flies emerged in the midril_e of April 1969 (135 days after deposition of the bait in the burrow, see Section IV). Immature stagest Puparium, golden/brown, translucent. Length, 4.5 mm. vvidth, 1.8 Similar to that of 42.

C.fimetaria (Figure 9) in general form. Anterior spiracular processes (Figure 11), sessile, black palmate structures with up to eight digitate papillae.

Subg. Fungobia Lioy.

9. C.fimetaria Specimens collected: numerous individuals; 25M 17F caught on five separate occasions in the suction trap at 4ft. (Trap B) from April to July. Monthly records: 1 - 12. Habitats: rabbit burrow entrances in woods; small mammal run in grass; badger faeces in "pit"; "bedding" from badger set; rabbit droppings. Breeding records: 213M 194F were bred from boiled grass bait deposited in rabbit burrows (see Section IV, for details). Laboratory observations: pairs of newly-emerged flies were placed on Type A and B Media at 20°C. Adults survived, but no eggs were laid. Only on one occasion was copulation observed in the laboratory; the pair remained together for 80 minutes, but no eggs were laid subsequently. 43.

J.Jongevity 2G days (male and female). Immature '3tages Pubarium (:'figure 9) Typical Copromyza puparium (see description at beginning of section) Length, 3.3 MA. 'iidth (at segment VII) 1.1 mm. Anterior spiracular processes (Pigure 9C) sessile, black, palmate structures with up to seven blunted papillae, irregularly arranged. Anus on ventral surface of segment XII has three clear discs of unknown function. The terminal projections of the posterior spiracles are greatly reduced. Third instar larva (figure 10), white, elonLate cylinder tapering at anterior end, distinctly blunted at posterior end. Length, 3.8 mm. Titidth, 0.6 mm. The first head-segment (Pigure 10E) bears a pair of small two-seEmented antennae. The anterior spiracles on The prothoracic segment are represented dy a pair o-f: sessile, palmate colourless structures with 5 - 7 digitate papillae. The buccal opening is surrounded by rows of smaJa sclerotised "teeth". Posterior spiracular processes on blunted terminal projections (:Figure 1CP). 44.

10. C.nitid,. ,p(-cimens colL,;cted: 9i' 14:i' (none in suction trap material). Lontilly records: 1 - 12. Tabitats: 1ca littei in entrance to rabbit burrows; rotting fungi ( .involatus) in wood.

11. C.roserii Sp- cimens collected: 431!: 25F (pairs in copula collected in uctooer). 1M 1F caught in suction trap at 4ft. (Trap 3) on two separate occasions in June. Monthly records: 1 - 5, 6, 7 - 12. Habitats: in leaf litter in woods; on rotting fungi (R.ochroleuca, mellea Quel., P. involutut). ''Jaboratory observations: pair of wild-cauglit flies on Ty-0e 3 medium observed in copula on two occasions 3 - 4 days after capture, but no eg:s were laid.

Subg. 'iorborillus Duda.

12. C.costalis. Specimens collected: no individuals were collected directly. 2i caw'ht in suction Trap at 4ft. on 2/3:10:61. 45.

.onthly recordsr 4 - 9, 10, 11.

13. Specimens collected: ]J. caw.lit in suction trap 3 at /12't. on 7.5%53. ,onchly records: 4 - 12.

14. U.sordida Specimens collected: 1iN caught in suction trap at 4ft. (2rap B) on 4.7.62. Monthly records: 5 - 9.

15. -;.uncinata. Specimens collected: 1I 211. 21.i 15' caught in suction traps (2M caught in Trap A at 30ft.).

-Lonthly records: 1, 3 - 11.

16. C .vitripennis Specimens collcted: 5M 14i1 caught in suction trap 3 at 4ft. on fifteen occasions.

Copromyza allen

17. C.equina. Specimens collected: 1M iF. 5M 12F caught in suction traps (1M in Trap A at 3Uft.) on fourteen occasions. 46.

Monthly records; 1 - 12. LLabitats: on compost.

lb. C.similis Specimens collected: 25-11. 15f' em caught in suction Crap at 4ft. on eighteen oc,:asions.

Jonthly records: 1 - 12. I-Labitats: on sheep dung on decaying; lawn mowin,?s in garden tip.

19. C.stercoraria :';pecimens collected: 11J. caught in suction trap .3 on 19.6.61. Monthly records: 1 - 12. Immature Stages: puparium figured and described by Goddard (1938).

Genus Ieptocera Olivier

The pupP.ria of fourteen species of :Aeptocera nave been previously figured: Vogler (19(;C), L.ciliosa (probably TJ.caenosa); Idchards (1930), L.zosterae, L.caenosa, TJ.claviventris and L.penetralis Collin; Goddard (193), nine si:;ecies (cited individually 47. in the following text); hafez (1939c), L.digitata (Duda); Egglishaw (1960), L.zosterae. The general description which follows is based on information from these authors, and from the descriptions of sixteen additional puparia figured here. Leptocera puparia vary greatly in size. In colour they rane from white, to golden/brown, pale yellow and black/brown. Their shape is a fairly constant elongate-cylinder, with the tapered anterior end flattened dorso-ventrally, and the Posterior end truncate. Segmentation is usually distinct, and in some species a number of longitudinal foveae are formed by the dorso-ventral com- pression at the sides of particular segments. The cephalopharyngeal skeleton of the larva remains, adhering internally to the ventral surface of the anterior segments. The anterior spiracular processes of the prothoracic segment have characters which are distinct for each species (or group of species). The dorsal surface of the puparium is covered with numerous fine transverse lines of varying extent. On the ventral surface the rows 48.

of hooks and smaller spines of the larva are usually visible on the antero-ventral margins of segments IV - XI. Segment XII is extensively wrinkled and bears the ventral anus. The terminal projections of segment XII, which bear the posterior spiracles, are variable in length and thickness, and the orientation of the spiracular plates differs. Each spiracular plate is usually surrounded by radial tufts of bristles. The larvae of only two Leptocera species have been previously described: Rafez (1939c), L.digitata; Tigglishaw (1960), L.zosterae. Laurence (1955) has figured the anterior spiracles of h. clunipes, halugubris, L.silvacica, and L.pseudoleucoptera, and the posterior spiracles characteristic of the subgenus Liinosina. Leptocera larvae show great similarity in form. The third instar larva is always white and translucent, but of varying length. It is cylindrical in shape, tapering towards the anterior end, and slightly at the posterior end. The head segment bears a pair of short two-segmented antennae, and sometimes there are rows of sclerotised "teeth" 49. around the buccal opening. The distinguishing specific eetures are the anterior spiracular processes which are colourless unsclerotised appen- dages of the prothoracic segment. The antero- ventral margins of segment IV - bear rows of .pine spines, with, in some cases, an additional row of large nooks on segments V - XI. Both posterior spiracular projections of segment XII bear a terminal plate which is often surrounded by radial tufts of fine bristles. The form of the cephalopharyngeal skeleton does not appear to differ between species (See Goddard 1930). The eggs of seven Leptocera have been previously figured and described L.silvatica and L.heteroneura (Goddard 1938); L.acutangula, L.moesta (Hamer 1941) and I.zosterae (Egglishaw 1940). In this paper the eggs of another eleven species have been figured (Figures 13, 18, 19, 23, 28, 32, 38, 41, 44). All the eggs are white and there is apparently little variation in the ovoid shape, which is flattened dorsally and convex ventrally. The main specific difference is in the arrangement 50.

of the two longitudinal hatching lines, which are on the dorsal surface, and which often enclose a flattened slightly concave area, the "sole" or median area (Hinton, 1960). The hatching lines are sheets or flaps of the chorion of varyin length and form. They are often extended into respiratory processes to a reater or lesser decree. In L.diFitata, L.lugubris and .acutanula the processes are present as a pair of long; anterior filaments, while in species such as L.silvatica and L.claviventris these are reduced to a row of papillae on the margin of the hatching line. A micropyle is present as a distinct group of cells in an antero-dorsal position between the hatching lines. Siclosion takes place when the cnorion splits along the hatching lines, so that the sole lifts off and the larva emerges (Figures 19 and 41). The external chorionic reticulation of these eggs has only been investigated here under phase-contrast illumination, and it appears to be similar in all species. Numerous interconnecting hexagons give a honeycomb pattern; the depression in the centre of each hexagon is apparently composed of numerous 51. indentations. 'finis sculpturing may be more or less pronounced, and varies in the amount, of surface area it covers. cine reticulated chorion and the marginal papillae probably form a plastron the kind described by ?Hinton (1960) in the eg s of Calliphora erythrocephala

Subg. Leptocera Olivier.

20. L.fontinalis Specimens collected e 21M 26P. 12M 202 caught in suction traps (2M in Trap A at 30ft.) from April to

3onthly Aecords: 1 - 12. labitats: rotten fungi in woods; badger faeces in "pit"; "bedding" from badger set; leaf litter in woods. Laboratory observations: Breeding experiments: a single wild-caught female kept on medium Type A, produced egs. Puparia were formed after 19 days. Longevity: 32 days (female). Immature .staes: Fuparium (2igure 12) golden/ brown, translucent. Length 3.0 - 3.3 mm. 52.

(at se6ment VII) 1.1 mm. Anterior spiracular process (Riure 120) black, stalked palmate with up to five pale sessile ppillae. Sides of s - ments II and III dorso-ventrally compressed on both surfaces formin distinct longitudinal foveae. Se,7ments IV to IX have longitudinal foveae extending the length of each segment on the dorsal surface only. The fine transverse lines on the dorsal surface of segment IV - X extend round to tne ventral surface. There are no hooks in addition to the rows of spines on the ventral surface of segments IV - XI. The anus consists of two clear semicircular areas. The posterior spiracular projections are short and outwardly directed.

21. I.caenosa. Specimens collected: 1F. 91d 62 caught in the suction traps (1Y in Trap A at 30ft.) from May to October. lonthly records: 2 - 3, 4, 5 - 12. 1 , abitats: decayed lawn mowings. J3readinp: records: 1k 4Jj' bred from boiled grass bait deposited in rough grassland (October). trie feale bred out from bait in ra6bit burrow in 53.

September (See Section IV). Laboratory observationso hredeen and Taylor (1964) have described the life-cycle in some detail. the flies were reared on Type S medium in tie lalioratory. Virgin females laid eL:s within 3 days after euergence, and would continue to lay up to 180 - 2&) egs without a male for periods up to 26 days after emergence. The eg,s were infertile and failed to develop. If a male was introduced into the rearing chamber, copulation occurred almost immediately. The pair remained in copula for 20 to 30 minutes, and the female laid fertile egs on about the second day after copulation. As many as 72 fertile e!-;;s were laid over a seven-day period. Copulation occurred more than once, and was observed for 25 minutes in a 14 day old female and a 12 day old male. Third instar larvae were observed within 7 days of ev-layin; and these pupated from the 20 to the 22 day a.L ter tne egs were laid. The wnole life cycle w s between 2 - 37 days. ix)ngevity 19 days (male); 26 days (female). Immature Sta[7es Freden and Taylor (1964) have described the larva and puparium, and Richards (1930) 54. figured tine puparium. The of tnis species has not previously been described. The (FiTire 13) is white and opaque. Length, C.6 cm. Width, 0.2 mm. Shape, ovoid flattened dorsally. The dorsal hatching lines are represented by an incomplete circle of minute marginal papillae at the antero-dorsal end of the egg, enclosing a distinct micropyle. The chorionic reticulation is the characteristic hexagonal sculpturing. Under phase-contrast each chorionic hexaon appers to enclose numerous indentations.

22. JJ.oldenber,j_. Specimens collected: no specimens collected directly. i:Onthly records: 3, 5, 7. breeding record: one female bred out from boiled grass "exit" in rabbit burrow- tunel (See Section IV). Immature staes: Puparium (Figures 14 and 15) golden/brown, translucent. Length, 2.85 mm. Width (at segment VII) 0.85 AM. Shape, characteristic elongate-cylinder. Anterior spiracular process (Figare 15C) black, sessile with up to four sub-palmate blunted papillae. Segmentation distinct on dorsal surface. Ventral surface: 55. eight groups of spines on segments V - II, with no large hooks. Posterior spiracles on blunt terminal projections. The cephalopharyngeal skeleton of the third instar larva (as it appears in the puparium) is illustrated in :.:. 0igure 15D. There are no obvious departures from the normal structure and arrangement of sclerites, as figured by Goddard (1938) for various 1,eptocera species.

23. L.curvinervis. Specimens collected: 2M 1F (628M 622P in suction trap material, see Section III for details). Monthly records: 2 - 6, 7, 8 - 12. Habitats: On compost in open situation; in small mamA.al run in grass.

Subg. Rachispoda Lioy.

24. L.varicornis Specimens collected: one male was caught in suction trap at 4ft. (Trap 3) on 31.7.63. Monthly records: 4, 5, 7 - 9.

25. L.lutosa Specimens collected: 3M 6F were caught in the suction trap at 4ft. (Trap 13) from June to September. 56.

Lonthly records: 1 - 9, 11.

26. h.limosa Specie ens collected: 6m 62 in suction trap at 4ft. (Trap 3) from June to laugust, and in October.

-Monthly records: 1 - 9, 10.

27. h.breviceps form cryptochaeta Specimens collected: 2M in suction trap at 4ft. and 1M at 30ft. (Traps B and A). Likmthly records: 2 - 7, 8, 9, 10.

Subg. Spinotarsella Richards.

28. L.humida Specimens collected: 24M 212. 371I 33F collected in suction traps at 30ft. and 4ft. honthly records: 1 - 11. Laboratory observations: Attempts to set up a culture at 20°C using; medium Type E were unsuccessful. The adults survived, but failed to copulate or produce any eg7zs. Longevity: 19 days (female). 57. dubg. Opacifrons Duda.

29. L.coxata. pecimens collected: 1441 1741'' were collected in the suction traps at 30ft. and 4ft. (Traps A and B). Monthly records: 1 - 12.

Subg. Fteremis Rondani

30. L.fenestralis Specimens collected: 23M 67F. 11M 15V collected in suction traps A and B (1M 3F in Trap A at 30ft.). Monthly records: 2 - 11. Habitats: rabbit burrow entrance. Breeding records: lh bred from a puparium collected from grass cuttings in June. Laboratory observations: attempts to set up a stock culture on Type A medium were unsuccessful. A single wild-caught female laid 12 eggs. 9 puparia developed, and 2 long-winged females emerged after 8 days. The complete life cycle from egg to adult was 27 days. Longevity: 13 days (female). Immature stages: -kuparium (Figure 16) golden/brown,

58.

translucent. Length, 2.6 mm. Width (at segment VI) u.75 mm. .21.terior spiracular processes (TA.gure 160) black, sessile, palmate structures consistinj, of up to 3 blunted -papillae. Segmenta- tion distinct. (Segments II and III have lateral longitudinal foveae) l'osterior spiracles borne at the end of blunted truncate projections. white; length, 0.67 mm. Width, 0.2 mm. Two distinct hatching lines run the length of the egg, and are continuous around the antero-dorsal margin. The whole surface of the egg has a hexagonal sculptured chorion.

30a. Pam nivalis Collin (1956) established that L.nivalis (Ealiday) is a short-winged form of L.fenestralis. Specimens collected: 12M 511? (none in suction traps). Monthly records: 1 - 5, 7, 3, 9, 10, 11. Habitats: on grass cuttings in garden tip. Laboratory observations: Attempts to set up stock culture on Type A medium failed. One isolated wild-caught female produced 17 eggs over a 10 day period. Only one puparium was formed; a short- winged female with an open vein emerged after 14 59. days pupation. The whole life cycle was 23 days. Longevity: 23 days (female). Immature stai es: the eggs were similL:,r to those of L.fenestralis and the single puparium which was obtained (Fip;ure 17) is apparently identical to that of L.fenestralis.

Subg. Thoracochaeta Duda.

31. L.zosterae Specimens collected: lii in suction trap at 4ft. (Trap i3) on 28.5.64. Lontnly records: 1 - 4, 5, 6 - 12. Immature stages: Richards (1930) figured the anterior spiracles of the puparium, and Egglishaw (1961) described the life-cycle in detail and figured the egg, larvae and puparium.

Subg. Chaetopodella Duda.

32. L.scutellaris Specilaens collected: 37M 2810. 121M 78F collected in the suction traps at both heights. (see Section III for details).

60.

Monthly records: 1 - 12. Habitats: rotten fungi (A.silvicola, P.involutus, R.ochroleuca); on decayed lawn mowinus in garden tip. Laboratory observations: wild-caught females were placed on media Types A, 13 and D, and although the adults survived, no eggs were laid. Longevity: 33 days (male) 53 days (female).

Subg. Functicorpus Duda

33. L.cribrata Specimens collected: 2M 32.

monthly records: 1, 2, 4 - 6, 7, 9, 10. habitats: rotten fungi in woods (either coniferous or deciduous). Laboratory observations: a single wild-caught female was kept on medium Type D, but no eggs were laid; a male was added after 20 days. Longevity: 24 days (female).

Subg. Limosina Macquart.

34. L.silvr,tica Specimens collected: 54Pi 55F. 61.

Monthly records: 1 - 12. Habitats: leaf litter at entrance to rabbit burrow. Laboratory observations: wild-caught individuals survived on Type A and Type C media, but no eggs were laid. Longevity: 21 days (male and female). Immature stages the e P: and the puparium have been figured and described by Goddard (1938).

35. I,.beouaerti. Specimens collected: 14M 16F. 72 collected in suction trap 3 at 4ft. on 3.4.63. 1,onthly records: 3 - 12. Habitats: on fungus in wood. i3reedin records: all months of the year from "bait' (boiled grass) placed in rabbit burrow tunnels. (See Section IV for details). Parasites: Ashmeadopria sp., Fhaenopria sp., Trichopria sp. (all Proctotrupoidea); Spalangia sp. (Chalcidoidea); and fleidotoma sp. (Cynipoidea) all bred from puparia from rabbit burrows (see Section IV for details). Laboratory observations: newly-emerged individuals were continually available from bait-trapping 62.

experiuents described in detail in section IV. Although these adults survived for long periods on Types A, B and C media, there are no records of copulation or egg-laying. Cn two occasions wild-

caught females on Medium Type B laid up to 19 eggs over a 6 day period. It may be presumed that L.bequaerti probably requires a period of dispersal or prolonged flight activity before copulation and egg;-laying, although only one individual was identified from the suction-trap material. Longevity: Over 100 days (male and female). Immature stages: the puparium was described and figured by Goddard (1938). Epg (Figures 18 and 19) white. Length, 0.6 - 0.7 mm. Width, 0.2 - 0.3 mm. Two longitudinal hatching folds on the dorsal surface, with numerous blunt papillae along the margins.: Distinct antero- dorsal micropyle. Chorionic reticulation: large hexagonal thickenings all over the surface and between the hatching lines. Figure 19 illustrates the way in which the hatching lines break along their length when the lirst larval instar emerges, and the dorsal "sole" is lifted off. 63.

36. ischmitzi. specimens collected: 5M 1F. 7M 9P collected in suction trap at 4ft. (Trap 13). 14onthly records: 3 - 7, 0, 9, 10. Habitats: in woods, on rotting fungus; carrion (lamb carcass) and in leaf litter at entrance to rabbit burrow. (Richards (1930) records it only from the runs and burrows of mice and rabbits).

37. L.fungicola. Specimens collected: 10M 18P. 104M 147F collected in suction traps at 4ft. and 30ft. Habitats: rotting fungi in woods (including P.involutus, A.silvicola, and R.ochroleuca). Breeding records: bred from grass bait placed in rabbit burrows in June (14 male 14 female), July (15 male 9 female), August (1 male 3 female) and September (1 male 1 female) (see Section IV for details). Parasites: Phaenopria sp. and Trichopria sp. (Proctotrupoidea); Kleidotoma sp. (Cynipoidea) were bred from puparia collected in bait from rabbit burrows (see Section IV). Laboratory observations: stock culture set up on 64.

Type A medium. In June 1967 an apparently new species (here referred to as Species A, see Section II Part 5) was bred from grass bait placed in rabbit burrows (see Section 1Y). The roost obvious difference between Species and L.fungicola is the length of the scutellar bristles in both the male and female (Figure 47). A series of breeding experiments was devised in order to determine Whether species A and L.fungicola were two forms of the same species. 1) A separate stock culture of species A was set up on Type A medium at 2000 in order to determine whether oi:Ispriniz. with short scutellar bristles (L.fungicola) would be derived from parents with long scutellar bristles (Species A), and vice-versa. ii) Individual pairs of flies from the stock cultures of both types (-L. fungicola and Species A) were placed in separate breeding chambers (on Type A and Type B medium): a) Newly emerged male species A with newly emerged female of L.fungicola (10 pairs) b) Newly emerged male L.fungicola with newly emerged female of Species A (1C pairs) 65.

c) - ewly emerged male of jJ.fungicola with newly emerged female of iJ.fungicola (10 pairs) d) Newly emerged male of Species A with newly emerged female of Species A- (10 pairs) The results were as follows: the stock cultures continued to breed "true', i.e. in the Species A culture, long scutellar bristled parents continuously gave rise to long scutellar bristled offspring. The pairs of flies in a) and b) experiments failed to copulate or produce offspring, although the adults survived for up to 52 days. The breeding behaviour exhibited by pairs of flies in c) may be summarised in the following manner: copulation occurred within three days after emer,zonce. The female laid up to 50 eggs soon after copulation over a 4 - 5 day period. Puparia were formed on the 10 - 12 day after the commence- ment of egg-laying, and the adults (approximately equal numbers of male and female) emerged after a pupation period of 6 - 10 days. The whole life cycle took between 18 - 23 days from adult to adult. Attempts to rear the larvae of L.fungicola on nutrient agar were not successful. 66.

Longevity: 40 days (male), 52 days (female). Immature stages: the puparium was described and figured by Goddard (193b). Egg (:Figure 20), white, typical Leptoceran shape. Length, 0.4 mill. Width, 0.1 mm. No hatching lines. Usual chorionic reticulation.

38. L.vitripennis. Specimens collected: 231v1 18F Suction trap material: 115M 239P in at both heights from April to October. Monthly records: 1 - 10, 11, 12. Habitats: small mammal runs in grass and under heather; in leaf litter at entrance to rabbit burrow in wood. Laboratory observations: pairs of wild-caught flies kept on Type A medium at 20°C., but no copulation or egg-laying occurred. Longevity: 14 days (male and female).

39. L.3etaria. Specimens collected: 5M 5V. 114 collected in suction trap at 4ft. on 2.10.63. Monthly records: 7, 10, 11. Habitats: grass cuttings in garden tip; rabbit faeces in grass. 67.

Laboratory observations: wild-caught females kept on Type A and Tyne 3 media at 20°C. but no eggs laid. Longevity 30 days (female). z, 0 Spec collected: 2H 4P. 26M 27:Y collected in suction traps at 30ft. and 4ft. from April to October. Monthly records: 1, 3 - 8, 9, 10, 11. Habitats: grass cuttings, rotten fungus.in wood; carrion (dead squirrel in grass). Breeding records: 1M and 1F from decaying lawn- mowings (June and August). Laboratory observations: No life history data. Immature stages: Puparium, (Figure 21) colour golden/yellow, translucent, with characteristic bend at segment VI, so that pupa lies in posterior 2 of the puparium. Length, 2.9 mm. Width (at segment VIII) 0.6 mm. Anterior spiracular processes (Figure 21C) are black and spine-like with up to 4 elongated papillae, which are pale. Segmentation distinct. Arrangement of fine spines and hooks on the ventral surface as in typical Leptocera puparium. 68.

Posterior spiracular processes long, projecting outwards. Each terminal spiracular opening surrounded by tufts of fine bristles.

41. L.collini. Spe3imens collected: 3M 11P in suction trap at 4ft. (Trap B) from June to Jeptember. Monthly records: 5, 6, 7, 8, 9.

42. I.appendiculata Specimens collected: 38M 43P. 811 14P collected in both sucticya traps (11d 3P in Trap A at 30ft.) from Pay to September. Monthly records: on grass cuttings; carrion (dead rabbit). Breeding records: from compost (male and female in June) from grass bait in rabbit burrows (see Section IV), (23 male 38 female August), (1 male in September); from grass bait in small mammal run in grasE, (male and female in September). Laboratory observations: stock cultures set up on Type A medium at 20°C. Pairs of newly—emerged flies were placed in separate breedinL cnambrs on Type A medium. Copulation occurred 1 — 2 days 69.

after emergence. The female laid up to 50 eggs over a five day period. Puparia were formed 12 days after the eggs were laid, and the adults emerged after a period of pupation of 10 days. The whole life cycle took between 25 - 30 days. Immature stages: Puparium (Pigure 22) colour golden/yellow, translucent. Length, 2.4 mm. 'width (at seF;ment VII) 0.7 mm. Anterior spiracular processes (Pigure 220), black, spine-like, each with six long, pale tubercles. Segmentation distinct.. Ventral surface with usual rows of spines and hooks. The posterior spiracular projections are long and narrow; each spiracular plate bears four radial tufts of fine bristles. Third instar larva (Pigure 23). Length, 3.3 mm. Width (at segment VII) 0.6 mm. Segment I (2igure 23i) bears the usual pair of short two-segmented antennae; and there are rows of sclerotised "teeth" around the buccal opening, through Which the large mouth hook protrudes. The anterior spiracular processes (not figured) are long and tapering as in the puparium, but colourless and unsclerotised. The terminal plate of tune posterior spiracle is 70. surrounded by the usual radial tufts of fine bristles (Figure 232).

43. L.denticulata Specimens collected: 11;1 (May); 1M 3F collected in suction trap at 3Oft. (Trap A) in August and 1P in trap at 4ft. (Trap B) in July. Monthly records: 1 - 4, 5, 7, 8, 11. Habitats: small mammal run in grass.

44. L.flavipes. Specimens collected: 1M in suction trap at 4ft. (Trap B) on 17.7.62. Monthly records: 2, 4 - 9.

45. L.pseudoleucoptera. Specimens collected: 2P caught on separate occasions in suction trap at 4ft. (Trap B) in June and July. Monthly records: 6, 7, 8.

46. L.heteroneura. Specimens collected: numerous individuals. 1534 182E in suction traps at both heihts from April to October (see Section III for details). Monthly records: 1 - 12. 71.

Habitats: on decaying lawn mowings. Breeding records: 1 female bred from boiled grass bait placed in rabbit burrow in July (see Section IV). Laboratory observations: stock culture set up on Type A medium at 20°C. Pairs of newly-emerged flies were placed in separate breeding chambers on Type B medium, and kept at 20°C. Copulation occurred soon after emergence, and the first eggs were laid four days later. Each female laid between 19 - 42 eggs over a 13 day period. Copulation was recorded up to three times in any one pair. The eggs were laid on the filter paper or on the sides of the container. The first larvae emerged within 24 hours, and moved about on the surface of the filter paper, apparently scraping at it for nutrient. The first instar larval stage was from 1 - 3 days long. The second instar larvae (2 - 3 days) were more active, on occasions they burrowed into the filter paper to such an extent that it was rapidly broken up. These larvae apparently in- gested the filter-paper, since the gut was visible as a black line through the transparent body wall. Puparia were formed on the drier lid and sides of 72. the container, ,.nd sozietimes in the filter-paper remains, with only the anterior spiracles projecting. (Larvae which pupated completely submerged in a drop of water failed to develop). The pupal stage lasted from 7 - 9 days; and the numbers of the sexes in the emerging adults were approximately equal. The complete life cycles from adult to adult was 20 - 23 days at 20°C. Longevity: 21 days (male and female). Immature stages: The egg and puparium have been described and figured by Goddard (1938).

47. L.secundaria Specimens collected: 1M in suction Trap at 4ft. on 17.7.63. Monthly records: 5, 7.

48. L.moesta. Specimens collected: 16M 14P. 309M 403P in suction traps (see Section III for details). Monthly records: 1 - 12. habitats: at entrance to rabbit burrows. Laboratory observations: stock culture set up on Type A medium at 20°C. Pairs of newly emerged 73. flies were placed in separate containers on Type 13 medium. Copulation occurred on the second day after emergence, and subsequently up to thirteen days after emergence (on a maximum of 3 occasions). Pairing lasted from 25 - 70 minutes. The following is an extract from notes made on such an occasion: "the male was observed be on the female, who responded by walking rapidly around the breeding chamber. After about five minutes the pair became stationary, and remained so for one hour and ten minutes. The male continued to be active throughout copulation; on occasions all 3 pairs of legs were pulsated wildly in the air, and then the mid and hind-pairs would apparently grip the female, or be passed along the surface of her abdomen in a regular manner. (The male basi- tarsus of the hind leg was apparently used, in this species, to pin down the wings of the female). The female intermittently moved the mid- and hind- legs along her abdomen in a regular wing-cleaning movement. In this process the male sometimes became dislodged, and the only point of contact between the pair was at the genitalia." After 74.

separation the male was observed in vigorous cleaning movements: the hind-legs were rubbed together at the thickened basi-tarsal segment, and then one or other leg was passed over the projecting genitalia; viewed under low-power micro- scope it ap'„)eared that the basi-tarsus was inserted into the crevices between the genital sclerites. These observations show that the thickened basi-tarsal segment of the hind leg serves in part as a cleaning si7,7ucture; acting also as a means of holding the female during copulation, although the ability of the female to dislodge the male during pairing, does not suggest that this function is of prime importance. The female laid up to 130 eggs (average for 15 pairs: 44 eggs per female) beginning on the fourth day after emergence and continuing over a 14 day period. The egs were deposited irregularly throughout the breeding chamber. The eggs hatched witLin 24 hours, and the larval instars behaved in the same way as those of L.appendiculata. Puparia were formed up to 13 days after the egs were laid. F2he adults emerged after about 10 days. The 75. complete life cycle was from 20 - 30 days at 20°C. Longevity: 24 days (male and female). Inaature stages: Puparium (Figure 24) colour, pale-yellow. Length, 2.1 mm. Width (at segment VII) 0.75 mm. Segmentation distinct. Anterior spiracular processes, (Figure 24D) black, spine- like, with up to six pale papillae. Posterior spiracles borne at the end of long thick terminal projections of segment XII, each with 3 slits (Figure 24C) and radial tufts of bristles.

49. L.pullula Specimens collected: 2M 15P. 14M 135F in suction traps at both heights from April to October. Monthly records: 1 - 12. Habitats: crrrion (dead mole); rotting fungus (P.involutus) in wood; most commonly from decaying lawn mowings and small ma.mal runs in rough grass. Breeding records: 1F bred from boiled grass bait deposited in rabbit burrow in wood (July) (see Section IV); 4F bred from grass bait deposited in rough grass (August); 22P bred from grass bait placed in small mammal runs in grass (September). 76.

Laboratory observations: three stock cultures were set up with three wild-caught females on Type A medium at 2000. The first generation in all the cultures consisted entirely of female flies. Females from the F, generation were each placed in separate breeding chambers on Type B medium at 2000. The flies began egg-laying on about the fourth day after emergence, and continued to lay eggs over a twenty day period. Up to BO eggs were laid by any one female, and 25 - 90% of these eggs continued development. The eggs hatched within 24 hours, and the characteristic behaviour and duration of the three larval instars was similar to that observed in L.appendiculata. Puparia were formed throughout the container, and some larvae pupated within the macerated filter-paper with only the anterior spiracles projecting. The average length of the pupal stage was 7 days (from 4 - 12 days). The complete life cycle was 22 - 36 days (average of 26 days for 20 individual cultures). Isolated females caught on a number of occasions from different habitats also gave rise to all-female populations. 77.

A continuous culture of L.pullula was maintained in the laboratory for 30 months, during which time no males were produced. Longevity: 3b days (female). Immature stges: Puparium (Figure 25) colour, white, translucent. Shape, as in previous species. Length, 2 mm. Width (at segment VI) 0.65 mm. Anterior spiracular processes (figure 25C), spine- like with up to five pale papillae. Posterior spiracles borne at end of thick terminal projections with the spiracular plates directed inwards, and surrounded by tufts of fine bristles. The cephalopharyngeal skeleton of the third instar larva (:;'figure 26D), does not show any obvious points of difference from that of other species. Egg (Figure 26E) colour, white. Length, 0.5 mm. Width, 0.1 mm. Two dorsal longitudinal hatching lines extend the length of the egg, and enclose a "sole" which is slightly concave. Distinct antero- dorsal micropyie. The chorion has a dense reticulation of hexagonal sculpturing.

50. L.claviventris Specimens collected: 6M 7P (1M collected in suction 78.

trap at 4ft. (Trap B) on 1/2/3.9.61. Monthly records: 1 - 7, 8, 9 - 12. Habitats: rotten fungi (Lactarius deliciosus Fr. and Collybia sp.) in woods; leaf litter under bracken. Breeding records: bred out in large numbers (3621+ 368?) from boiled grass bait deposited in rabbit burrows (see Section IV); 4M 7F bred from grass bait deposited in woodland. Parasites: a large number of parasitic Hymenoptera were reared from puparia collected from the bait deposited in rabbit burrows (see Section IV for details), and included species of Ashmeadopria, Phaenopria, Spalangia and Trichopria. Laboratory observations: a continuous supply of newly-emerged flies was available from the bait- trapping experiments in rabbit burrows (see Section IV). Stock cultures were also set up on Type A medium at 20°C. Newly-emerged virgin females which were kept in isolation and placed in separate breeding chambers on Type B medium, laid up to a maximum of 12 eggs from 10 - 12 days after emergence. These eggs failed to develop, although 79.

the parent flies survived in the :breeding chambers for up to three months. Pairs of newly-emerged flies were placed on Type 3 medium in separate containers at 20°C. Copulation occurred on the 3rd or 4th day after emergence and lasted from 40 - 165 minutes. The following is an extract from notes made on one such occasion: in copulation the female made repeated wing-cleaning movements, in which the hind tarsi were wiped along the wing from front to back, both legs simultaneously. These movements and other movements involving the cleaning of the cerci resulted in the male becoming almost dislodged, the only point of contact between the flies then being at the genitalia. During copulation the female also walked intermittently around the chamber, and occasionally rubbed the fore-tarsi together in an apparent cleaning movement. The hind legs of the male were alternately hanging free, perpendicular to the surface on which the couple were, or the hind legs were vigorously pummelled on the female abdomen for up to 5 second periods. The mid- and fore-legs of the male were 80. apparently used in gripping the female." The pair separated after 65 minutes, and the male carried out a similar cleaning operation to that observed in L.moesta (Species 48). The ei!;Fs were laid soon after copulation or 2 - 4 days later. &ach female laid up to 100 eggs over a ten-day period, the eggs being deposited irregularly throughout the breeding chamber. The eggs hatched within 24 hours, and the larval instars behavecl in a way similar to those of L.appendiculata (Species 42). As in previously described species, the puparia were formed on the walls or lid of the container, or buried in the disintegrat- ing filter paper. The pupal stage lasted from 4 - 7 days at 20°C. The life cycle was completed in 20 - 30 days. The numbers of the sexes in the emerging adults were approximately equal. L.claviventris survived on nutrient agar (Type C medium), but no eggs were laid. Longevity: 20 days (male); 87 days (virgin female); 35 days (mated female). Immature stages: The puparium has been figured by Richards (1930), but, as illustrated, the 81.

structure of the anterior spiracular processes differs from those obtained by myself (Figure 27D), which are more elongated and spine-like with up to four small pale papillae. I have looked at the puparia in the British Museum (N.q.) which were bred out by Professor F.V. Theobald, and from which the illustrations in Richards (1930) are derived, and find that the specimens are damaged; the main body of the anterior spiracular processes having been broken off. Also, the whole cephalic cap of the puparium has been glued onto the card so that it is difficult to determine its structure. I would conclude that Richards' drawing was made from a faulty specimen, which would explain the aparent difZerences in structure alluded to above. The structure illustrated in Figure 27 can then be taken as the characteristic form of the anterior spiracular processes in the puparium of L.claviventris. First instar larva (Figure 29G). Colour, white. Shape, cylindrical. Length, 0.8 mm. First segment with the usual pair of two-segmented antennae. Anterior margins of segments IV - XI with rows of 82.

spines and hooks Posterior spiracles situated on two dorsal projections of segment XII, the spiracular plates surrounded by radial tufts of fine bristles, Much-simplified cephalopharyngeal skeleton viith mouth hooks, dorsal bridge, and dorsal and ventral cornu. Third instate larva (Figure 27A). Colour, white. Length, 2.3 mm. Pair of two-segmented antennae on segment I. Rows of scierotised "teeth" around buccal opening. Anterior spiracular processes (Figure 27B) on segment II are unsclerotised palmate structures. Ventral anus on segment XII is surrounded by spines. Posterior spiracular plate (Figure 27C) surrounded by radial tufts of fine bristles. Egg (Figure 28). Colour, white. Length, 0.5 mm. Width, 0.2 mm. The two longitudinal hatching lines are continuous antero-dorsally, and have numerous papillae along; their margins. The chorion has an uninterrupted reticulation of hexagonal sculpturing.

51. L.ochripes Specimens collected: 5M 2F. 18M 34F collected in suction traps at both heights in April and June to October. 83.

i.onthly records: 1 - 9, 10, 11, 12. Habitats: small mammal runs in grass. Laboratory observations: one wild-caught female survived for 10 days on Type A medium, but no eggs were laid.

52. L.clunipes Specimens collected: 22M 35F. 616M 579E collected in suction traps at both heights (see Section III for details). lionthly records: 1 - 12. habitats: carrion (dead mole, and dead rabbit); "bedding" refuse from badger set. Breeding records: bred in numbers (41M 60F) from boiled grass bait deposited in rabbit burrows (see Section IV); and from grass bait deposited in long grass (July and August). Parasites: it is difficult to distinguish between the puparia of flies in the L.clunipes group so that parasites listed under 11.(L.)- palmata (Richards) may have emerged from the puparia of L.clunipes. Laboratory observations: attempts made to set up stock cultures on Type A medium were unsuccessful, 84.

although occasional wild-caught females produced sole eggs (up to 12) which continued developillent and resulted in the emergence of a few adult flies. But no continuous culture was achieved. Virgin females reared from rabbit burrow bait traps, survived for 17 days on Type A. medium, but did not lay any eggs. Longevity: 13 days (male and female); 17 days (virgin female). Immature stages The puparium has been figured and described by Goddard (1938). The anterior spiracular processes of bred specimens of L.clunipes examined here show a wide range of variation in the orientation of the papillae to the main axis of the process. Goddard (1938) interpreted this as an interspecific variation, suggesting that the angle between the papillae and the long axis may be a means of distinguishing between the puparia of L.cluniues and L.palmata. However, the specimens illustrated in Figures 30 and 31 demonstrate that this variation is intraspecific and on the whole there is litle to distinguish between the puparia of these two species. (The angle between the main 85. axis of the process and the cephalic cap of the puparium also shows great variation, and apparently depends upon the position of the larva at pupation). The number of papillae on each spiracular process is not fixed, and the length of the .,Thole structure varies from 0.1 - 0.25 mm. Egg: (Figure 32). Colour, white. Length, 0.6 mm. 0.2 mm. Two longitudinal hatching lines have minute marginal papillae. Distinct antero-dorsal micropyle. Chorionic reticulation of thickened hexagonal sculpturing.

53. L.palmata. Specimens collected: 30M 21F. 1M collected in suction trap 3 on 26.6.61, and 1P on 30.4.64. Monthly records: 1 - 12. Habitats: leaf litter in wood; on pile of lawn- mowings in open grassland situation. Breeding records: bred in large numbers (262M 334F) from bait deposited in rabbit burrows (see Section IV); bred from grass bait placed in small mammal runs in grass (5M 6P - July); and grass bait deposited in grass tussocks (31 9F, July and October). 86.

Parasites: As explained above, the puparia of L.palmata are practically indistinguishable from those of L.clunipes. This means that parasite preferences for one or other of the host species canaot be detected from these records. A large number of Hymenopteran parasites were reared from puparia collected from rabbit burrows (see Section IV for details) and include species from the following genera: Ashmeadopria, Phaenopria, Spalangia and Trichopria. Laboratory observations: newly-emerged males and females were kept on Type A and B media, but no regular breeding occurred and therefore no life- history data were recorded. Longevity: 29 days (female). Immature stages: the puparium has been figured and described by Goddard (1938). Figure 31 illustrates the intra-specific variation which may occur in the anterior spiracular processes, and which has been discussed above. Egg: (Figure 32) exhibits the same form as that of L.clunipes, which has been described above. 87.

54. T.manicata Specimens collected: 118M 61P. 5M 51? collected in suction trap B at 4ft. in June, July and August. Habitats: badger faeces; rotten fungi (including Coprinus sp. and P.involutus.). Monthly records: 1 - 7, 3, 9 - 11. Breeding records: bred in numbers (235M 1931) from grass bait deposited in rabbit burrows (see Section IV); and from grass bait deposited in small mammal runs in rough grassland (60M 8919. Parasites: A large number of Kleidotoma sp. (Cynipidae, Eucoilinae) were reared from puparia collected in the rabbit burrow bait-traps (see Section IV), although some of these puparia may in fact be those of other species in the L.clunipes group. Laboratory observations: wild-caught and newly- emerged individuals were kept on Type A medium, but no regular culture was established. Copulation lasted up to 12 hours. The eggs hatched within 2 - 4 days after laying, and the period of pupation was 7 days at 20°C. The complete life-cycle was 21 - 24 days. Females which were kept in total 88. darkness at 20°C. also laid eggs. Longevity: 19 days (male); 32 days (female). Immature stages: the Ruparium has been figured and described by Goddard (1938). Eggs: the structure of the egg is similar to that of L.clunipos and L.palmata, with the hatching lines extending the length of the egg, and the chorion sculptured hexagonally.

55. L.talparum Specimens collected: 6M 5P. 5M 11P collected in suction traps at both heights from June to September. Monthly records: 1 - 5, 6, 7, 8, 9, 11, 12. Habitats: grass-cuttings; carrion (dead mole and rabbit in grass); leaf litter, rabbit burrow entrance; rotting fungus. Breeding records: 3M 8P bred from grass bait deposited in rabbit burrows in August and October (see Section Iv). Immature stags: Puparium figured by Goddard (1938).

56. Lobifrons Specimens collected: 5M 4F. 18Th lip collected in suction traps (2M 1.J, in Trap A at 30ft.) from June to September. 89.

Monthly records: 1 - 10, 12. Habitats: rotten fungus (A.silvicola) in wood. Laboratory observations: wild-caught individuals kept on Type A medium at 20°C. laid eggs, but the resultant puparia were inviable. Immature stages: Puparium (Figure 33). Colour, white and translucent. Length, 1.6 mm. Width (at segment VII) 0.6 mm. Anterior spiracular processes (Figure 33C), black, spine-like with up to four pale papillae. Posterior spiracles at end of short terminal projections of segment XII.

57. L.parapusio. Specimens collected: 2M 3511% 4? were caught on four separate occasions (in June, July and October) in the suction traps (2 in Trap A at 30ft., 2 in Trap B at 4ft.). Monthly records: 1 - 5, 6, 7 - 12 (2); 6, 7 M. Habitats: small mammal runs under grass. Breeding records: bred from fungi (11 females in October) and from grass bait deposited in rabbit burrows (4 females in July and April). Laboratory observations: a stock culture was set up of wild-caught females on Type B medium, 90.

(cultivated mushrooms), and also on nutrient agar (Type C medium). The first generation of these cultures were all female. The virgin females were each placed in a separate breeding chamber on Type

D medium, and ept at 90°C. Ti•ggs were laid on the fifth day after emergence. L. large number of these eggc are laid in regular lines along the gills of the mushroom cap, others were scattered irregularly throughout the breeding chamber. Each virgin female laid between 40 - 100 eggs (average 51 eggs) over a five-day period. The majority of these eggs were inviable, but some continued development, and were truly parthenogenic. The first instar larvae emerged within 24 hours, and moved about the surface of the mushroom. This stage lasted for 1 - 2 days. The third instar larvae were very active, and burrowed into the fungus so that only the posterior spiracles projected. Pupation occurred after 4 days; the puparia being formed on the surface of the liquify- ing fungus, or on the drier sides of the chamber. (Larvae which pupated completely submerged in the liquid mushroom, failed to complete their development). 91.

The pupsrial stage was 6 - 7 days at 20°C. The .whole life-cycle took 16 - 22 days. The high mortality at the egg stage may have been due to the rapid liquifaction of the mushrooms in the container, so that the eggs became submerged. L.psrapusio was also reared parthenogenically on Type A medium. No males were produced throughout the breeding experiments, although parthenogenic cult res were started with wild-caught females on a number of different occasions. Longevity: 33 days (female). Immature stages: Puparium (!J'igure- 34) Colour, golden/ brown, translucent. Length, 2.2 mm. Width (at segment VII) 0.8 mm. Anterior spiracular processes (Figure 34C), black, spine-like with up to 6 short, pale papillae. Posterior spiracles on pair of thickened projections of segment XII. Egg: (Figure 38B) Colour, white. Length, 0.6 mm. Width, 0.3 mm. Elongate ovoid, with same features as egg of L.clunipes, but apparently no papillae on margin of hatching folds. Third instar larva (Figure 35E) Colour, white. Length, 3.4 mm. 1st segment (Figure 35F) with usual 92. pair of two-segmented antennae, and rows of sclerotised "teeth" around buccal aperture; pair of lateral unsclerotised spiracular processes, feather- shaped with up to 12 papillae. Posterior spiracles (Figure 35G) on segment XII surrounded by radial tufts of fine bristles.

58. L.spinosa Specimens collected: 1M was collected in the suction trap at 4ft. (Trap B) on 22.4.65. Ebnthly records: 3, 4.

59. L.pseudonivalis Specimens collected: 1Y. Monthly records: 2, 4, 9, 10, 12. Habitats: small mammal run in grass; rabbit burrows. Breeding records: 5M 9 bred from grass "bait" deposited in rabbit burrows in June, July, August and September (see Section IV). Immature stages: Puparium (Figure 36) Colour, golden/yellow. Length, 2.6 mm. Width (at segment VII) 0.85 mm. There are two longitudinal foNeae on dorsal surface of segments II and III. Segmenta- tion, indistinct. Anterior spiracular processes 93.

(Figure 36C) black, spine-like with up to six pale blunted papillae. Posterior spiracles on end of short thick tubercles, with flattened spiracular plates directed inwards.

60. L.rufilabrs. Specimens collected: 3M 32. Monthly records: 1 - 12. Habitats: grass cuttings; leaf litter; rabiJit burrow entrance.

61. L.luteilabris Specimens collected: 13M 11P. 70M 116P collected in suction traps at both height's from April to October. Monthly records: 1 - 7, 8, 9 - 12. Habitats: grass cuttings; rotten fungus in wood. Breeding records: bred from bait deposited in rabbit burrows (46M 492 July and August. See Section IV); and from boiled grass "bait" deposited in small mammal runs in grass (18M 31P in August and September), and grass tussocks (11M 172, March and August). Laboratory observations: wild-caught individuals 94. kept on Type A medium at 20°C. Complete life- cycle was completed in 17 days. Larvae buried into the agar with only the posterior spiracles projecting. Puparia with submerged anterior spiracles failed to develop. Immature stages: Puparium (Figure 37). Colour, golden/yellow, translucent. Length, 2.6 mm. Width (at segment VII) 0.9 mm. Anterior spiracular process (Figure 37C) long, black, spine-like with 5 - 8 short, pale papillae. Segmentation, indistinct. Posterior spiracles on terminal projections of segment XII, with flattened spiracular plates. Egg (Figure 38k). Colour, white. Length, 0.5 mm. Width, 0.18 mm. Hatching folds run the length of the egg and are continuous antero- dorsally with marginal papillae. (:Features similar to egg of Ii.elunipes).

Subg.lid2,7L.,.a Duda

62. L.spinipennis. Specimens collected: numerous individuals. 47M 85F in suction traps at both heights from April to October. 95.

Monthly records: 1 - 12 Habitats: on fungus (A.silvicola) in wood (6]1 2M). Laboratory observations: stock culture set up on Type A medium at 20°C. Attempts to breed this species on nutrient agar (Type C) were unsuccessful. The adults survived for up to 7 days, but no eggs were laid. Longevity: 14 days (male). 8 days (female). Immature stages: Puparium (Figure 39) Colour, golden/yellow, translucent; Length, 1.95 mm. IA_dth (at segment VII) 0.75 mm. The anterior spiracular processes (Figure 390), long black spines with 5 - 6 short pale papillae. Segmentation distinct. Posterior spiracular plates flattened and inwardly directed at end of short terminal tubercles of segment XII.

Subg. Elachisoma Rondani.

63. L.aterrima Specimens collected: 6i 9] (none in suction traps). Monthly records: 4, 5, 7, a, lo, 11. Habitats: rotting grass cuttings. 96.

Laboratory observations: wild-caught females kept on Type A medium at 20°C:. The females laid eggs, and the complete life cycle took 26 days. Immature stages: Puparium (Figure 40) Colour, golden/yellow, translucent. Length, 1.6 mm. Width (at segment VII) 0.6 mm. Anterior spir&cular processes,(Figure 40B), long black spines with up to seven pale papillae. Segmentation distinct. Longitudinal foveae on segment VIII, IX and X. Posterior spiracles borne on long terminal tubercles. Third instar larva cephalopharyngeal skeleton shown in Figure 40C.

ERR: (Figure 41). Length, C.35 mm. '4idth, 0.1 mm. One of the eggs in :figure 41 shows eclosion, where the first instar larva is emerging. The chorion of the egp: has a dense reticulation of numerous small circular indentations.

64. L....pilosa. Specimens collected: 1M 5F were caught in the suction traps on six separate occasions. (1M 4F at 4ft., Trap B; 1? at 30ft., Trap A) in July, August and September. Monthly records: 6, 7, 8, 9. 97.

Subg. Trachyopella Duda.

65. h.atomus. Specimens collected: numerous individuals. 1H 12 were caught on separate occasions in the suction trap at 4ft. (Trap B) in April and August. Ddonthly records: 4, 5 - 8, 11. Habitats: decayed lawn-mowings, in the deepest layers on a semi-liquified substrate. Breeding records: 2E 1P bred from decayed lawn mowings. (June). Laboratory observations: stock culture set up on boiled grass cuttings at 20°C. The flies bred over several generations, and puparia were obtained, but no life-history data was compiled. Immature stages: Puparium (Figure 42) colour, golden/brown, translucent. 'length, 1.8 mm. Width (at segment VII) 0.6 mm. Anterior spiracular processes (Figure 420), same colour as rest of puparium, sessile, palmate with up to four papillae. Segmentation distinct. Segments II, III and X with longitudinal lateral foveae. Posterior spiracles on long terminal projections, with radial tufts of bristle encircling the spiracular plates. 98.

66. L.leucoptera. Specimens collected: 1F (14M 17J collected in suction traps at both heights from June to October) Monthly 3,, cords! 6, 7, 8, 9, .1.0. Habitats: at entrance to rabbit burrows. Laboratory observations: wild-caught female kept on Type A medium at 20°C. After 22 days puparia were formed in the breeding chamber, and three males emerged 7 - 12 days later. The whole life cycle was completed in 30 days. Immature stages: Puparium (Figure 43) Colour, yellow, translucent. "length, 2.1 mm. (at segment VII) 0.7 mm. Segmentation distinct on dorsal oUrface. Anterior spiracular processes (Figure 43C) black, spine-like, with up to four pale papillae of medium length. Posterior spiracles borne at end of long terminal projections, the spiracular plate surrounded by the usual radial tufts of bristles.

67. 1.coprina. Specimens collected: numerous individuals. (none in suction traps). 99.

Ylonthlv records: 1 — d. Habitats: decayed lawn mowings in lowest layers. Laboratory observations: stock culture set up on Type A medium at 2000. -.',reeding occurred, but no life history data was compiled. Immature stages: The puparium has been described by Goddard (1338). Egg (Figure 44) characteristic Leptoceran shape, dorsally flattened, ventrally convex. Iltching lines, with marginal papillae, extend the length of egg. No chorionic reticulation apparent.

Subg. Coproica dondani.

68. L.acutangula. Specimens collected: 1M. 1841+ 200? collected in the suction traps at both heights from April to October (see Section III). honthly records: 2 — 4, 5, 6 - 11.

69. 11,vagans. Specimens collected: 411 4F, one pair in copula in iay. 56M 68F collected in suction traps at both heights from April to October. 100.

Honthly records: 2 - 8, 9, 10, 1. Habitats: decayed lawn mowings. Laboratory observLtions: wild-caught individuals kept on boiled grass cuttings at 20°C. but no eggs laid. Longevity: 6 days (male and female). Immature stages: Puparium, described by Goddard (1938).

70. L.ferruginata. Specimens collected: 31 3P. 19M 14F collected in suction traps at both heights from hay to August. Eonthly records: 1 - 12. Habitats: carrion (dead squirrel) in long grass. kites: 1M collected in July had a mite attached to the abdomen (not identified so far). Laboratory observations: wild-caught individuals kept on boiled grass cuttings at 20°C. but no eggs laid. Longevity: 6 days (female).

71. L.lugubris. Specimens collected: 5M 8F. 58n 72P collected in suction traps at both heights from April to October. 101. konthly records: 2 - 9, 10, 11. Habitats: carrion (dead squirrel); fungus (A. silvicola) in wood.

72. L.pseudo17,gubris. gyecimens collected° numerous individuals. 11.t 20 collected in suction traps (12 in Trap A at 50ft.) from June to September. i,,onthly records: 1 - 6, 7, 8 - 11. Habitats: decayed lawn mowings. Pates: female collected in August with 2 mites on abdomen. Laboratory observations: stock culture set up on boiled grass cuttings at 20°C. No life history data compiled. Immature stages: Puparium (Figure 45) Colour, black/brown, opaque. Length, 2.1 mm. 'Jidth (at segment VI) 0.5 mm. Anterior spiracular process (Figure 45C) long, black spines with up to eight pale papillae. Dorsal surface, segmentation indistinct, variously wrinkled. Posterior spiracles at end of broad terminal projections. Third instar larva (Figure 45D) a typical Letoceran 102.

larva. Cephalopharyngeal skeleton with no obvious points of difference. Anterior spiracular process, long feather-like, colourless appendage of prothoracic segment.

73. • " Specirens collected: numerous individuals. 11M 10'x' caught in suction traps (8M 7P at 4tt. Trap B; 3M 32 at 30ft. Trap A) from May to August. Monthly records: 2, 3, 5 - 7, 8, 9, 10. Habitats: rotting grass cuttings. Laboratory observations: stock culture set up on boiled grass at 20°C. The life-cycle was completed in 18 - 28 days. Period of pupation varied from 5 to 9 days. Immature stages: Puparium (loigure 46) Colour, white, opaque. Length, 1.5 - 1.75 mm. \'idth (at segment VII) 0.7 mm. Anterior spiracular processes (Pigure 46B), short, sessile, with 3 - 4 pale papillae. Segmentation indistinct. Patches of spines on ventral surface barely discernible. Posterior spiracles at end of terminal projections, which are short and outwardly directed. 103.

5. DESCRIPTIUN OF A 1:24 SPECIES.

Leptocera (Species A) n. sp. A small species (M F length 1.7 mm; wing 1.2 mm.), resembling L.fungicola as described by Haliday (1836). Although Richards (1930) observed that Collinp (1914) found Haliday confused two species under his name fungicola; one of which Zetterstedt (1847) described as L.vitripennis. L. (Species A) differs from L.fungicola in the following points: Thorax (Figure 47): scutellum short, with the apical bristles nearly twice as long as the basal pair, not as in L.fungicola where the apical bristles are hardly longer than the basal pair. Abdomen (2igures 48, 49 and 50): Yale genitalia with posterior gonapophyses of aedeagus distinctly curved and thinner, genital forceps larger and more distinctly bifid, than those of L.fungicola. Wings (Figure 51): sixth vein is less sinuous than that of L.fungicola, otherwise there are no obvious points of difference. Immature stages: Puparium (Figure 52), similar to 104. that of L.fung.icola as described and figured by Goddard (1938). Pale yellow, translucent. Length 1.8 mm. Width (at segment VII) 0.6 mm. Anterior spiracular processes (Figure 52C), sub- palmate with up to 4 sessile blunted papillae. Segmentation distinct, sides of segments II and III dorso-ventrally compressed to form longitudinal foveae. Posterior spiracles borne on end of two thick terminal projections from the dorsal surface of segment XII. Third instar larva (Yigure 52D): Length 1.9 mm. Pair of two-segmented antennae on head segment. Anterior margins of segments IV - VIII with the usual locomotory hooks. Posterior spiracular plates surrounded by radial tufts of fine bristles. Egg: similar to L.fungicola (Figure 20), with uniform reticulation on chorion and no distinct hatching lines. Specimens collected: 6M 7F. 51 caught in suction traps at 4ft. ('J') and 30ft. on four occasions. Monthly records: 3, 4, 6 — 10. Habitats: on rotting fungi (P.involutus, R. ochroleuca) in woods; rabbit burrows; small mammal runs in long grass. 105.

Localities: Silwood Park and Windsor Great Park, Berkshire, Breeding reccrds: 132M 1681.'' bred from boiled grass bait placed in rabbit burrows (see Section IV) from July to Os sober inclusive. 5M 4F bred from boiled grass bait deposited in, small mammal runs in grass in August to September. 2' bred from rotting fungus collected from Windsor Great Park in July (flies emerged 28 days later). 7M 10F bred from bait in an adult trap (Figure 2) placed in long grass. Parasites: it is difficult to distinguish the puparia of Species A and L.fungicola so that some parasites listed for the latter species may be parasites of the puparia of Species A. The following parasites have been identified only to genera: Phaenopria sp., Trichopria sp. (Diapriidae, Procto- trupoidea), Kle:'.dotoma sp. (.11;ucoilinae, Cynipoidea). Laboratory observations: stock culture set up on Type A medium. individual pairs of flies reared on Type B medium. The stock culture was continuous for up to 2 years, and the flies continued to produce offspring with long scutellar bristles. 106.

A series of experiments was devised in order to determine whether copulation would occur between individuals with long scutellar b=ristles and individuals with short scutellar bristles (see notes on L.funp;icola in Section II). The life cycle of Species A was completed within 25 days at 20oC, and was similar to that of L.fungicola. Longevity: 52 days (male); 26 days (female). The following specimens (31 42) labelled L.fungicola in the British Museum (N. N.) have long apical scutellar bristles: British collection: 1F collected by L. Parmenter on 11.7.55 at Coshieville, Perths (det. J.C. Deeming 1965). world collection: 3M 1F collected by P.2. Holmes on 25.6.34 (12) and 3.7.34 on Grimsey Isle, N. Iceland (The angle between R24.3 and the costa more acute). The following specimens (2L 22) labelled L.fungicola in the Verrall-Collin collection at the Hope Depart- ment of Entomology (Oxford) have long apical scutellar bristles (M mid femora with 5 basal posterior bristles; pale stalked haltere; greater angle between R2+3 and costa. 107.

1I' collected by J.1. Collin on 20.4.34 at Barton Mills. 2' collected by J.-:;. Collin on 15.3.52 at Kincraig. 1M collected by J.E. Collin on 22.3.52 at Kincraig (R2 ,3 Facu to costa). (The collection of L. Parmenter (recently received by the Bri *sh hiuseum (N.H.)) and the haliday Collection in the National Museum, Dublin have not yet been investigated.) In Duda's key (1918) for the subgenus Scotophilea this form (Species A) runs down to Limosina exigua Rondani (a later name for L.fungicola employed by Rondani (1880), but now discarded) in couplet 21 (p. 38) and because of the length of its apical scutellar bristles, the form of the posterior gonapophyses of the male genitalia and the straight- ness of the sixth vein, it may be separated from L.exigua at this point. Duda (1918) made no mention of the length of the scutellar bristles in the L.exigua/L,vitripermis group of the subgenus, but Richards (19N) states that in this group the "scutellum is short, with short bristles, the apical ones being usually hardly longer than the scutellum." 108.

) In Richardos key (1930) for the }3ritish species of Sphaeroceridae, this form (species A) runs down to L.funizicola (Hal.) in couplet 55 (p. 279), where it may be separated from T..funFicola at this point by the features mentioned above. 109.

6. GETMIC KEY TO PWP.,:itIA

The following provisional key to the three British genera has been compiled from data extracted from following sources: Vogler (1900); Richards (19302:; Goddard (1938); Hafez (1939c); Egglishaw (19L:0): Fredeen and Taylor (1964); and Deeming and Knutson (1966). 1. 'kith no posterior spiracular projections on last segment, (always blackish-brown; a compact ovoid) Sphaerocera Latreille. 'Kith definite terminal posterior spiracular projections on last segment, (range of colours) 2 2. Posterior spiracles almost sessile, at end of very short terminal projections of last segment. Black, palmate or sub-palmate anterior spiracles. (golden brown, compact, elongated ovoid over 3.0 mm. long)

6 • • 0 • • • * . . 0 . CoTromvza Fallen. Posterior spiracular plates at end of longer tubular projections of last segment, often with radial tufts of bristles Leptocera Olivier. 110.

1J.T4:;CTIOZ III .LNAIJYSIS (2J SUCTION TAA.? RECORDS

1. IhTROJUCTION.

The aim of this study was to estimate the total numbers of the Sphaerocerid aerial fauna from just above ground level to thirty feet; to identify those species that occur in the aerial fauna, and to determine their numerical relations to each other; to see whether there is any seasonal variation in flight activity, and to elucidate the nature of that activity: whether there is any evidence for swarming behaviour or definite migrational flights; finally to deduce, if possible, whether there is any direct relation between the theoretical catchment area with known habitats in the vicinity of the traps (and therefore with a known fauna), and those species which actually occur in the aerial samples. Sphaeroceridae are well-suited to passive aerial distribution: they are small, weak-fliers with a large expanse of wing compared to body mass (Glick, 1942). There are a number of records where Sphaeroceridae have been collected by aerial sampling. Hardy and Milne (193d) have identified at least three species collected at heights of up to 500ft. using kites and tow-nets. Glick (1939) fitted insect-traps onto a small aeroplane, and collected 537 specimens of Sphaeroceridae over a five-year period between 20 and 1,000 feet; with a few specimens at 5,000 ft. Freeman (1945) using nets flown from fixed masts, obtained 938 Sphaerocerid individuals between 10 and 277 ft. over an eighteen-month collecting period. There are a few records where Sphaerocerids have been identified in the food of aerial feeding birds such as the swift (Parmenter and Owen 1954; Parmenter 1954b; Lack and Owen 1955). Lack and Owen (1955) found that the Sphaeroceridae formed 7% of all Diptera taken by the swift, and that these and other small insects (2 - 5 mm. in length) were particularly abundant in meals taken in poor weather, when the larger insects were not flying. 112.

2. TH2 TRQ?S TS.

The material dealt with here was obtained from two suction traps which had been operated at Silwood Park over definite periods for a number of years. The traps were of the 18" propeller type developed by Johnson and Taylor (1955 a and b), and described by Southwood (1966). The catches were separated into 24 hour samples (except at weekends when each sample represented a 72 hour catch). The material from each catch '- ad been preserved in alcohol and stored. Complete records were available for the five-year period (1961 - 1965). Table I shows the periods of operation of the suction traps, and the map in figure 53 indicates the position of the traps relative to each other, and the nature of their catchment area. Trap A was situated at the top of a 30ft. tower, and Trap B rested on the ground, so that it effectively sampled from a height of 4ft. The results dealt with here are from a regular series of 24 hr. catches taken at weekly intervals (255 catches). TABLE 1

PERIODS OF OPERATION OF THE SUCTION TRAPS

HEIGHT TRAP (feet) 1961 1962 1963 1964 1965

TRAP A 30 21.4 - 10.10 1.5 - 10.9 19.4 - 31.10 9.4 - 11.10 2.4 - 6.10

TRAP 13 4 21.4 - '10.10 1.5 - 31.7 19.3 - 31.10 9.4 - 11.10 2.4 - 6.10 114.

3. ThS AaAIAL '1J'AITNA.

The Sphaeroceridae from each suction trap sample were picked out, counted and identified to species. Only a few specimens were so damaged that identification was impossible. Table 2 shows the total numbers of Sphaeroceridae in each trap, and the number of daily samples investigated for each year of the five-year period. On some days there was a marked increase in the numbers of a particular species, and therefore an examination of the preceding and subsequent daily catches was made, in order to assess the flight activity of that species over a longer period. This accounts for the differences in the number of samples examined from each trap in any one year. In 1962 Trap B failed after July 31st, so that no further material was obtained that year.

a. Composition of the 2auna. The suction traps A and 13 were operating in an open grassland situation (Figure 53), so it might be expected that species caught in the trap at 4ft. especially would be those associated with TABLE 2.

THE ABUNDANCE OF SPHAEROCERIDAE

The total number of Sphaeroceridae caught in two suction traps at different heights above ground level, over a five year period.

TRAPS YEAR 1961 1962 1963 1964 1965

Trap A (30 ft) 101 71 92 75 90 (27) (19) (23) (25) (1.9)

Trap B (4 ft) 1373 740 1700 855 2018 (31) (15) (36) (26) (29)

Note: The figures in brackets are the number of 24 hour samples from which the flies were taken. 116. the micro-habitat complex of open grassland. A total of sixty-six species was identified, and included species with a wide variety of habitat preferences. Thirty-one species were represented by less than ten specimens in the whole five year period, and mention of their occurrence in the traps has been made only in Section II. The remaining thirty-five species are listed in Table 3, which gives an indication of the numbers in which they occur and their frequency in the traps. 116. the micr -habitat complex of open grassland. A tal of sixty-six species was identified, and inc ded species with a wide variety of habitat preferen es. Thirty-one species were represented by les than ten specimens in the whole five year perio and mention of their occurrence in the traps has Veen made only in Section II. The remaining thirty-five species are listed in Table 3, which jives an ind cation of the numbers in which they occur and their requency in the traps. 117.

TABLE 3. THE TOTAL NUBERS 0 "ECIi: SPECIES AND THE NUMBER OF OCCASIONS ON WHICH THEY OCCUR In EACH TRAP THROUGHOUT THE FIVE-YEAR PERIOD (1961 - 65).

(The species are listed in alphabetical order).

laTABER OV INDIVIDUALS NUMBER OF OCCASIONS SPECIES TRAP A TRAP B TRAP A TRAP B

L.acutangula C 6 375 6 65 L.appendiculata 0 4 25 3 17 C.atra 0 1 36 1 27 L.bifrons 0 3 26 3 20 L.caenosa R 1 14 1 13 L.clunipes 1) 62 1533 37 118 L.collini R 0 14 0 10 L.coxata C 17 301 12 62 L.curvinervis D 14 1287 11 80 C.equina R 1 15 1 13 L.fenestralis R 4 22 4 17 L.ferruginata 0 10 23 10 19 L.fontinalis 0 2 29 2 17 L.fungicola C 16 235 14 60 L.heteroneura C 20 305 7 61 L.hirtula R 6 17 6 10 L.humida 0 13 57 13 32 L.leucoptera 0 12 19 8 14 L.limosa R 0 12 0 12 L.lugubris C 7 121 7 54 118.

Table 3 (Contd.)

NUM3ER 019 ITUMBER OCCASIOVS

A rf,i'lAP B TRAP A TRAP 13

L.mirabilis 0 9 49 8 24 L.moesta B 25 667 20 79 L.ochripes 0 6 46 6 33 L.pseudolngubris R 1 20 1 17 L.pullula' C 16 133 13 52 S.pusilla B 19 489 18 76 L.schmitzi R 0 16 0 9 L.luteilabris C 11 176 10 70 L.scutellaris C 11 188 11 61 C.similis R 0 23 0 18 L.spinipennis C 75 80 45 46 L.talparum R 5 11 4 10 C.uncinata 0 2 34 2 28 L.vagans C 17 106 14 45 C.vitripennis R 0 19 0 15 L.vitripennis C 11 346 7 92

Note: Category of abundance D: over 50( specimens in both suction traps (Dominant) C: 100 - 500 II If it If II (C.mmon) 0: 30 - 100 II If If II II (Occasional) R: 10 - 30 It II 11 It II (Rare) 119.

The frequency of occurrence (i.e. the number of occasions on which flies occur in the traps) in Table 3 demonstrates that the abundance of individuals of a particular species in the traps is not a regular phenomenum. Some species such as C. similis, C.uncinata and L.fenestralis occur in low numbers on a number of occasions, whereas other species such as L.fungicola, L.heteroneura and L. moesta occur in larger groups but with less frequency. As has been already mentioned, on some days there was a marked increase in the numbers of a particular species in Trap B. Table 4 demonstrates these daily variations for seven species, including the four most-abundant species L.curvinervis, L. clunipes, L.moesta and S.pusilla. Lack and Owen (1955) investigating the food of the swift (Apus apus), found similar daily variation in the number of some insects in the swift's meals. Assuming that the swifts catch those insects that are available, Lack and Owen (1955) postulated that these changing numbers re- flected real changes in the aerial fauna and could be assessed in terms of "emergence, death, and perhaps the weather."

120. TART 4. WLRITION IN THE NUM.1211S OF SOLE :'32SCIES ON SICOTI;SSIVE DAYS IN THAP B.

L.curvinervis. Date:- June 1961 26 27 19M 511 15E 9F July 1962 16 17 18 131 10Y 61d 2? 41v1 7F It 1965 20 21 22 2M 6? 32M 302 441'I 27F August 1963 27 28 29 6M 91 14M 16Y 2M IP

II 1965 18 19 3M 2? 18M 18F

L.clunipes. Date:- April 1961 24 25 22E 2111 Gil 12 May 1961 1 2 181' 152 12M 91' June 1963 18 19 20 10M 5? 10M 11F 10M 10P July 1965 20 21 22 3M 811 23M 10Y 7M 10]? August 1963 13 14 15 7M 7P 9M 10Y 3M 2 1963 27 28 29 6M 11F 15M 102 2M 12 1965 25 26 1011 13P 16M 14P 121. Table 4 (Contd.)

L.moesta. Date:- June 1961 26 27 211 1OF 8I1 7F July 1962 16 17 18 35M 30? 271,E 412 51i 1OF August 1963 13 14 15 1514 7Y 181x1 17F 91.1 11F u U 27 28 29 2M 51' 18M 171+'

S.pusilla. Date:- July 1965 20 21 22 1111 21F 51M'_ 13P 311' 35P August 1963 27 28 29 31 211 lad 6F 3M 2F

L.acutangula. Date:- July 1962 16 17 18 4M 4710 31,1 411

L.heteroneura. Date:-July 1965 20 21 22 22i 30F 16M 18F 5M 2F

L.fungicola. Date:-July 1965 20 21 22 3M 5 10M 12F - 2F August 1963 13 14 15 311i 3F 15M 12F 51:1 4F 122.

A number of immature or teneral flies were found in the trap-samples at Silwood Park (see 3g of this section), demonstrating that flies in such a condition are capable of some flight, or on the other hand subject to passive aerial distribution. The condition of immaturity in a specimen was taken as a lack of sclerotisation, or when the cuticle was distinctly pale and soft. However, the presence of teneral specimens in a sample did not coincide with the large numbers shown in Table 4. Only on one occasion, 24.4.63, was there any evidence for a "mass-emergence" when ten of the twentynine individuals of L.vaans in that sample were immature. Thus, it is not possible to account for these large numbers simply in terms of a mass emergence. The data shown in Table 4 may be assessed in other behavioural terms, perhaps as evidence for a mass-migrational flight. There are few observations of such behaviour in the Sphaeroceridae, but Richards (1930) records that species, such as C.equina, L.clunipes and $.curvipes, which are associated with dung, are prone to fly together in large numbers, particularly on the first warm days of the year. 123.

bung, like all decayini:- organic matter, is a transient habitat, which undergoes a series of changes from the moment of deposition. Laurence (1955) emphasised the dynamic aspects, when he demonstrated that some Sphaerocerids will only visit a cow-pat when it is fresh and moist, whilst others will colonise it later when it is more dry. It is perhaps important for species which utilise dung as a food source, to be capable of mass-flights in order to locate and colonise freshly deposited material, when the existin micro-habitat no longer suits their requirements. Such a behavioural mechanism may account for the large numbers of L.clunipes, S.pusilla and L.acutangula on successive days. These species are all corinonly associated with dung, although L.clunipes and S.pusilla (see Section II) tend to be more cosmopolitan in their habits. L.curvinervis and L.moesta are found more commonly in association with damp herbage, small mammal runs in grass and compost, and their abundance on certain days cannot necessarily be assessed in terms of a mass migrational flight. 124.

:.!,g:71ishaw (161) observed mass flights of a different fiture- when he studied L.zosterae on the wrack-beds of the sea-shore. In this case, the seaweed refuse on wilicn tie species lives may be subject to rapid periodic ilooding, so that the ability of the flies to rise as a group by a coordinated reaction to the warning stimulus of the oncoming wave would seem to be essential for survival. It is perhaps not possible to attribute such a response to the more terrestrial species found in Silwood Park.

b. Variation in the fauna at different heights. The majority of flies were caught in the lower of the two traps - _trap :3 at 4ft. (see Table 2). Only one species, h.spinipennis occurred in both traps in almost equal numbers (Table 5). Those species that were dominant members of the aerial fauna as a whole did not occur in any great number in Trap at 30ft., but were apparently confined to Trap B.

c. Variation in the fauna throughout the year. The traps were operated in periods from 125.

TABLE 5

VARIATION IN THE SPHAEROCERID AERIAL FAUNA AT DIFFERENT HEIGHTS: THE PERCENTAGE OCCURRENCE AT 30 FEET. (Species which occur at least five times in Trap A )

SPECIES CATEGORY NUMBER. IN TOTAL NUMBER % IN TRAY A TRAP A IN BOTH TRAPS

L. spinipennis 75 155 48.4 L. leucoptera 0 12 31 38.7 L. ferruginata 0 10 33 30.3 L. humidor 0 13 70 18.6 L. mirabilis 0 a 58 15.5 L. scutellaris 11 199 8.7 L. fungicola 16 251 6.5 L. heteroneura 20 335 6 L. luteilabris 11 137 5.9 L. coxata 17 318 5.3 L. clunipes 62 1195 5.2 S. pusilla 19 508 3.7 L. moesta 25 712 3.5 L. vitripennis 11 357 3.1 L. acutangula 6 381 1.6 L. curvinervis 14 1301 1.1 126.

March to October, and the highest numbers of all Sphaeroceridae were found from June to August. This is probably an indication of the population build up through the season. Glick (1939) found that as the temperature increased in May, and there was a general emergence of pupating insects, the maximum numbers in the aerial fauna were achieved in the upper air at this time. Freeman (1945) found a definite peak in the number of all Sphaerocerids in May at the highest levels he sampled. The variation in the average catch-size of the four dominant species is shown in Table 6 and Figure 54. S.pusilla, L.moesta snow the same general pattern of abundance, L.curvinervis, however, has a steady build-up in numbers, reaching a peak in August. The sesonal abundance of L.clunipes has no special peaks, a fact which has been sub- stantiated by field collections made on the ground (see Section II).

d. Variation in the Sex Ratios. The total numbers in each sex of those eighteen species represented by a total of 50 or TABLE 6

VARIATION IN THE AVERAGE CATCH-SIZE OF THE FOUR nOMINANT SPECIES (a - d) THROUGHOUT THE YEAR AT FOUR FEET.

MONTH APRIL MAY I JUNE JULY AUGUST SEPTEMBER OCTOBER Total no. a. of catches 6 113 22 I 29 22 12 3 L. CURVINERVIS Mean catch size 3.2 2.2 9.6 17.4 21.6 3.2 1.3 Total no. h. of catches 0 22 26 28 I 17 18 5 L.'CLUNIPES Mean catch size . 11.6 7.5 11.9 8.5 I 10.1 6.9 2.6 Total no. c. of catches 5 7 I 21 1 24 20 5 L. MOESTA Mean catch size 7.7 1.3 6.4 i 13.5 8.3 3.4 Total no. d. of catches 5 I 18 19 j 11 13 S. PUSILLA Mean catch size 5.4 I 1.2 6.1 i 10.4 4.3 2 128. TABLE 7.

SEX-RATIOS OF THE EIGHTEEN MOST ABUNDANT SPECIES IN THE SUCTION TRAP MATERIAL (Total for whole five year period).

SPECIES MALES FEMALES SEX-RATIO

L. scutellaris 122 77 158.4 L. humida 37 33 112.1 L. curvinervis 683 618 110.5 L. clunipes 616 .579 106.4 L. mirabilis 29 29 100 L. acutangula 184 197 93.4 S. pusilla 235 273 86.1 L. heteroneura 153 182 84.1 L. vagans 56 67 83.6 L. coxata 144 174 32.8 L. lugubris 57 71 80.3 L. moesta 309 403 76.7

L. fungicola 104 147 70.7 L. luteilabris 71 116 61.2 L. spinipennis 55 100 55 L. ochripes 18 34 52.9 L. vitripennis 118 239 49.4 L. pullula 14 135 10.4 129.

more individuls in the suction traps are given in Table 7, with the calculated sex-ratio for each species. The low sex-ratio indicated in L.pullula is expected, since this is a ps.rthenogenic species (see Section II). The fourteen males attributed here to L.pullula may in fact contain some of L. moesta, from which it was sometimes difficult to distinguish in the preserved material. Changes in the sex-ratio of the four dominant species throughout the year are indicated by Table 8. There is apparently no particular season when either sex is more actively in flight.

e. Influence of the weather. It is well estahlished that the occurrence of insects in the air is influenced by such factors as temperature, relL,Aive humidity, rainfall and wind velocity. Glick (1939) found that the greatest numbers of small Diptera were present in the air at temperatures between 75° - 79°P, and that the insect aerial population reached a peak when surface wind speeds were between 5 - 6 m.p.h., above this the numbers decreased. Freeman (1945) recorded

TABLE 8.

CHANGES IN THE SEX-RATIO OF THE FOUR DOMINANT SPECIES (a - d) THROUGHOUT THE YEAR AT BOTH HEIGHTS.

MONTH APRIL' MAY I JUNE JULY- AUGUST SEPTEMBER OCTOBER

a. L. CURVINERVIS M. F MF MF F !F M IF F

10 1 15 14 119 99 269 236 240:240 18 120 1 3

SEX- 107.2 120.1 114 100 1 RATIO 90

b. L. CLUNIPES M F M IF M /A IF N ;F M 1 !F I F

49 48 f 98 i92 164i157 1331115 87 j92 71 156 9 5 1 SEX- 102.1 1 106.5 RATIO 104.4 115.7 94.6 1 126.8 180 TABLE 8 continued

CHANGES IN SEX-RATIO.

_ H MONTH I APRIL MAY JUNE JULY AUGUST M SEPTEMBER I OCTOBER j 1 C. L. MOESTA /1 IF A. F M IF F MI F M F MI F 1 8 1 32 1 124 184 L 19 64 176 ni 91 I 5 12

1SEX- 1RATIO 25 11.1 84.2 67.4 88.1 33.1 d. S. PUSILLA M IF F IF M IF M F M. M

14 113 7 8 51 172 107 1150 38 23 18 i9 o SEX- jZATIO 107.6 37.5 70.8 71.3 165.2 200 132.

that temperature had the major influence, and the maximum number of insects were found in the air in conditions of high temperature and low humidity. He also stated that low wind velocities, up to 12 m.p.h. are more favourable for aerial insect activity. Both authors found that rainfall tends to inhibit the flight of insects or as Freeman put it "wash the insects out of the air". At Silwood Park daily records of rainfall, temperature and relative humidity were available -for the period 1961- 1965. There are, however, no records of wind-velocity for this period and the nearest centre with recorded data is London Airport (Heathrow), which is some fifteen miles ta the north-east of Silwood Park. In view of the distance between the recording site and the position of the suction-traps, it was decided that it was not feasible to use the data in any assessment of the effect of wind-velocity on the occurrence of Sphaerocerids in the trap-samples. An estimate was made of the number of Sphaerocerids in the air at each of five temperature ranges, and the results were as follows:- at the 133.

range 5 - 7°C there was an average of 8.4 flies per 24-hour catch; at 8 - 10°C there w-7:e 24.9 flies; at 11 - 13°C, 47.6 flies; at 14 - 16°C, 71 flies, and at 17 - 19°C there was an average of 30.2 flies. However, the temperatures in the range 14 - 16°C tend to occur in those months when the adult flies would be expected to be abundant on the ground (i.e. in May, June and September). So that, in fact one is merely recording the fact that the ground populations of Sphaerocerids are at a peak, and consequently more flies are available to become part of the aerial fauna, rather than the fact that Sphaerocerid flight activity is particularly increased at these temperatures. Similarly, fewer flies appear to fly in the range 17 - 19°C. Temperatures in this range tend to occur in the height of summer, July and August, when, as previous authors have shown, Sphaerocerid populations tend to be at a minimum. Freeman (1945) stated: "The appearance of many species in the air was more to be associated with the life history, than with the immediate 134. effect of temperature"; and Lack and Owen (1955) have stressed the fact that, when attempting to correlate aerial trapping records with the weather, the changing numbers of a species on the ground must be considered. In the light of these statements, and in view of the fact that there are no adequate figures, for the terrestrial populations of the predominant species in the suction-trap samples, it is not possible to make any correlations or assessments of the ways in which the Sphaerocerid aerial population is influenced by the weather.

f. Parasitic Attack. Several specimens of a number of species in the trap material at both heights had mites attached to their bodies, the main attachment site was the abdomen. None of the mites have so far been identified. In most cases it appeared that the stylets of the acarine were thrust into the intersegmental membranes between the sclerites of the fly, and this was probably an indication of an ectoparasitic relationship. Some of the flies 135.

thus affected had a severely reduced or shrivelled abdomen. Two species, L.clunipes and L.luteilabris were apparently infected by a parasitic fungus, the fruiting bodies and hyphae of which could be seen protruding through the intersegmental membranes. The general appearance of the fly was otherwise un- changed, and experience in the laboratory has shown that individuals thus affected may survive for several days. The fungus has not been identified so far.

g. Teneral flies. It has been mentioned previously, that a number of teneral or immature flies were found in material from both suction traps. The numbers were sporadic, and were not confined to any particular month. Immature specimens of a total of 26 species were identified.

h. Comparison of the suction trap fauna with other collections made in the vicinity of the traps. It has already been stated that there is no quantitative data for the ground populations 136.

of Sphaeroceridae occurring within the vicinity of the suction traps. Nevertheless, certain species were collected regularly within the area covered by the map in Figure 53, and their absence in the suction trap material is worth noting at this point. No specimens of the short-winged nivalis form of L.fenestralis were identified in the trap material, although this species was found regularly in tussocks and small mammal runs in rough grass (E, H and M in Figure 53), together with the long-winged L. fenestralis, L.pullula, and L.vitripennis, which do occur in the traps. number of species such as L.silvatica, L.parapusio, L.claviventris, L.bequaerti, L.palmata and L.manicata were found with similar regularity in the areas of woodland (J and L in Figure 53) near the suction traps, but these species are absent or occur rarely in the trap material. Freeman (1945) emphasised the relation between the aerial insect fauna and the vegetational type immediately above which aerial samples were taken. It may be that the indications given by the material dealt with here will make it possible 137.

to distinguish quite clearly between groups of Sphaerocerid species occupying a general grassland habitat (as sampled by the suction traps) and those occupying a woodland situation. 138.

SECTION IV THE SFHATIROCERID PAUNk IN THE BURROVIiS OF TNE RABT3IT (ORYCTOLAGUS CUNICULUS L.).

1. INTRODIP:T1(;h.

Sphaeroceridae are comonly found in the runs and nests of small mammals. Richards (1930), in a classification of the major Sphaerocerid habitats, records thirteen species (2 - Copromyza; 11 - Leptocera) which occur at the entrance to rabbit burrows in the British Isles. Hackman (1963a) in his work on the dipterous fauna in burrows of the voles (Nicrotus arvalis, M.agrestis, and Clethrionomys glareolus), collected 16 species (1 Sphaerocera, 5 - Copromyza, 10 - Leptocera), and gives a review of various authors who have work- ed on the ecology of nest and burrow invertebrate fauna. Hackman (1963b) records nine Sphaerocerid species (5 Copromyza, 4 - Leptocera) in collections made from the burrows of Clethrionomys rufocanus and the Norway lemming (Lemmus lemmus), and notes that the great annual fluctuations in the populations of these rodents results in instability of the 139. dipteran population. Richards (1964) described three new Leptocera species, which ere collected from the burrows of the pocket gopher in Illinois, by means of molasses bait. Although Rubbel and Goff (1939) and Ross (1944), studying the burrow fauna of the pocket gophers of ;Florida and Texas respectively, give no Sphaerocerid records. Davies (1934) in a survey of the nest fauna of the short- tailed voles (Ylcrotus aFrestis and M.hirtus) collected only one species (L.pullula) but his method (3erlese funnel) was probably inadequate for the collection of adult flies. Judd (1961) collected a single male Limosina sp. from debris in the burrow of the woodchuck (Marmota monax L.) in Ontario. Deeming: and Knutson (1966) collected one species (L.palmata) from the nest cLivity of a badger set in Surrey. Hackman (1967) using traps with various baits collected a total of 26 species (2 - Sphaerocera, 4 - Copromyza and 20 - Leptocera) in the burrows of the mole (Taira europaea) and rat-vole (Arvicola teryestris) and the vole (Pitymys duodecimcostatus) in Northern urope and Southern Spain. Vanschuytbroeck (1943) in an assessment 140. of the four principal biotopes in which Sphaero- ceridae occur in the hauts-Pagnes in Belgium, records five species (1 - 0opromyza, 4 - Leptocera) from nests and caves. Trapping methods for insects in general were dealt with extensively by Southwood (1966), who makes a basic distinction between traps that catch the animals randomly and those that attract them in some way. Hackman (1963a) has described in detail the sampling procedure he employed in small mammal burrows. He has given figures of the Barber pit-fall traps and funnel traps he used to retain the adults and which contained a breeding substrate, from which flies were subsequently reared. (1964) collecting beetles used a modified pitfall trap with fish "bait". The deposition of a breeding: substrate within a particular habitat introduces a new factor in selection. It may be, that the conditions for egg-laying of species which normally occur in the habitat, are not provided by the bait; or that species from outside the habitat are attracted to 141. the bait. (This factor has been dealt with in greater detail in 4a of the Section.) In this present study, the breeding habits of the Sphaerocerid tunnel fauna of rabbit burrows were measured by the collection of puparia rather than adult flies. The method used was the deposition within the burrow of an attractant "bait", which provided a breeding substrate to which the adult flies had free access, without being artificially retained. In this way an assessment was made of the breeding; potential for individuals of those species occurring within particular rabbit burrows in Silwood Park over an eighteen month period (June 1967 - January 1969). Since each rabbit burrow must be regarded as a distinct and separate microhabitat it was important to be able to use the same rabbit burrows throughout the experimental period. Therefore it was essential to have a sampling method which caused the minimum of disturbance to the habitat, and which allowed the passage of rabbits and other mammals within the tunnel. A total of thirty-one Sphaerocerid species 142.

(1 - Sphaerocera; 6 - Copromyza; 24 - Leptocera) were found in association with the rabbit burrows in Silwood Park, eight of which were collected ex- clusively from the burrow tunnel. Twelve of the species collected have previously been recorded by Richards (1930) from this habitat. 143.

2. 1 LI,THODS

a. Description and Location of Sites. The Sphaerocerid fauna of twenty rabbit burrows was investigated in two sites in Silwood Park. The first site, an area known as 'ood Bank (designated J on the map in Figure 53) was a north-facing steep bank with a thick ground cover of bracken (Pteridium aquilinum) and an upper storey of beech (gagus sylvatica) with an intermittent leaf canopy. There was much accummulation of leaf litter in the entrances of the burrows, some becoming completely blocked at certain times of the year. This was the location for eleven of the burrows. Another two were situated on a north-facing grassy slope to the east of the bracken area, where the beeches were replaced by small oaks (Quercus robur). The second site, at the eastern edge of the park in an area known as Pound Hill, was the location for the seven remaining burrows. small knoll with numerous seedling elms (Ulmus procera) which had a thick leaf canopy so that there was little ground flora except for the 144. occasional group of nettles (Urtica dioica). The bare sandy soil at the burrow entrances had a sparse accumulation of leaf litter.

b. Description of "Bait-trap". An attempt was made to devise a trap of a non-toxic inert substance, which would nevertheless be strone., enough to withstand. the movements of rabbits etc. within the tunnel. The term "trap" has been used for convenience and in a general sense, although strictly speaking; the device was not a trap, since the flies were not trapped or retained artificially. The device used was a cylinder of plastic netting (commercial "hetlon") with a 0.5cm. mesh (measurement length 13cm.; diameter of cylinder 4.5cm.) closed at each end with a disc of similar material (Figure 1). The mesh was of sufficient size to allow access by Sphaerocerid adults, and yet retained the bait effectively. each trap was filled with "bait", the lid was secured with thin non-corrosive wire, and the whole device pushed 18" - 24" down the burrow tunnel. The trap was tethered by wire to a bamboo stake at the burrow entrance. 145.

c. sampling Procedure. .F3ait-traps were deposited in each of the twenty rabbit burrows for monthly periods (28 - 31 days) continuously from June 1967 - January 1969. (Mxcept when traps deposited in the middle of April 1968, were left in the burrows until the end of May (approximately 42 days); the time scale for the two adjacent monthly periods being given as .April/May and June/July.) The °bait" used throughout the experiment was fresh grass that was boiled. This was readily available as lawn mowings, easily prepared, and could be tightly packed into the mesh cylinder, so that it retained its moisture and its attractant qualities. During the winter,months when there was no regular supply of lawn mowings, grass was grown in a greenhouse and cut by hand for use. On collection from the burrow, the trap was removed from its wire tether, and a trap with fresh bait was deposited. The exposed trap was placed securely in a polythene bag and returned to the laboratory. 146.

d. Extraction of puparia from Bait, and mergence of i_dult Plies. The bait contents of the exposed trap were emptied into a large water-filled bowl, and the trap itself was wasried in water so as to remove puparia, which sometimes adhered to the plastic neting. The puparia, were obtained by a method of direct flotation. The rotten grass bait soon separated out in the water, and discontin- uous agitation the puparia were released and floated to the surface, where they were removed by means of a thin brush. onto filter paper. Originally a solution of magnesium sulphate, which is non-toxic to insects, was used in order to decrease the specific gravity of the water (see Laden 1936), but this proved unnecessary since Sphaerocerid puparia have a low specific gravity, and float on the surface of untre,,ted wter. This method is easy to replicate without variation. Sphaerocerid puparia were easily distinguished from other Diptera, however, any doubtful specimens were retained until the adults emerged. Sphaerocerids made up the bulk of the insect fauna 147. in the bait, along with large numbers of J?sychodid puparia and occasional fhoridae. 11C data was collected on insects other than Sphaeroceridae. The viable, as opposed to the empty puparia, were each placed in a separate corked glass tube (2" x i"). These tubes were stacked in transparent plastic boxes on damp filter paper and transferred to the dark room of an outside insectary. The tubes were inspected daily (except at weekends), and the emergent adults identified and sexed. _Jrapty puparia, which occurred in the bait, and from which the adult flies had aparently already emerged before the trap was collected, were recorded and identified to species as far as was possible. '41-1en it was apparent that no more flies would emerge from the puparia in the insectary, these were rechecked and identified, and those that were parasitised returned to the insectary to await the emergence of the parasites. The data in this experiment are therefore based on the total numbers of Sphaerocerid puparia, obtained from bait-traps placed in each of twenty rabbit burrows, for every monthly period from 148.

June 1967 - January 1969. These puparia have been categorised as empty or viable, and the latter subsequently as inviable or parasitised. Emergence dates for each individual of the different species have been recorded. 149.

3. :AII;TEOR,atOCTIC±,L FACTORS.

The Sphaerocerid puparia collected from the twenty rabbit burrows nave been dealt with as a whole. No attempt has been made to isolate the conditions or to analyse the population fluctuations in any one of the burrows studied. each rabbit burrow must be regarded as a discrete microhabitat, with its own local variations. rL correlation of the varying conditions within each one of the twenty burrows, in order to make an assessment of the tunnel populations as a whole, has not therefore been attempted. hackman (1963a) in his investigation of the microclimatic conditions in vole burrows, found that the relative humidity or moisture content of the burrow was practically constant except in the entrance zone. Using a themograph and maximum- minimum thermometers he was able to measure the diurnal temperature variations in a typical burrow. He found that on a sunny summer day the burrow temperature variation had an amplitude of 4°C., whilst the outside soil surface snowed a range of 13°C. Throughout the winter the burrow temperature 150. never fell below -2°C., while outside the surface temperature fell to below -10°C. Ae concludes that in all kinds of vole burrows, extremes in the outside temperature will be evened out, and that the period suitable for active insect life in the burrows will depend on the macroclimate, sun exposure, and the nature and water content of the soil. It is perhaps sufficient to state that in a similar way the conditions within the enclosed space of the rabbit burrow tunnel can be expected not to fluctuate to such an extent as those outside, so that although the burrow fauna would be protected from extremes, nevertheless it would reflect the broad meteorological factors which affect the outside environment as a whole. Daily readings are taken at Silwood Park of such conditions as relative humidity and temperature. Table 9 shows the mean, maximum and minimum temperatures for each month of the eighteen month sampling period from June 1967 to January 1969.

151.

TABLE 9.

SIIJWCOD PARK: A(NT,_ ,Y fL,VF- A2-013.3S- 1967 - 1969.

14E4:1\1 la.XIMISIA MINI1:41.1111, (°C.)

1967 June 14.2 19.5 8.5 July 17.2 22.7 11.7 August 15.6 20.3 10.9 September • • 15.3 17.3 9.7 October 11.0 14.2 7.6 November 5.6 9.0 2.2 December 4.2 6.9 C.6 1(168 January 4.3 6.7 1.3 ebruary 2.2 5.2 -1.2 Earch 6.6 10.8 2.6 April 7.8 13.4 2.5 May 10.2 14.9 5.4 June 15.0 19.9 10.0 July 15.3 20.3 10.7 August 15.1 19.7 11.2 September • • 13.6 18.0 10.0 October 12.7 15.8 9.7 November 6.3 8.9 3.5 December 2.6 4.5 0.2 1969 January 5.8 8.2 3.0 152.

4. TH2 BUR1t0,4

a. Composition of the Jauna. Nineteen species were collected from the burrow tunnel (1 - Snhaerocera! 3 - Copromza; 15 - Leptocera). Two of these (S.monilis and C.roserii) occurred only as adults on the traps and were not bred from the bait material. In Table 10 the numbers of puparia of each of those species that were bred from the bait traps are listed. The number listed under L.palmata may not represent a true result. In this group of the subgenus Limosina (including L.manicata, L. luteilabris, L.clunipes, L.pseudonivalis, L.talparum, and L.parapusio) puparia are sometimes very much alike, and although on occasions there are obvious differences in size and colour which enable one to classify those particular puparia as L.manicata or L.luteilabris for example, on the whole the distinction is hard to make. The number treated here as L.palmata probably contains a number of puparia which belong to one of the other closely allied species. This, of course, only applies in 153.

TABLE 10. Total numbers of puparia (including empty, inviable and parasitised) obtained from bait deposited in rabbit burrows at Silwood Park, from June 1967 to January 1969.

SPECIES NUMBER

L.claviventris 8241 L.bequaerti 7007 L.palmata 970 C.fimetaria 520 L.manicata 524 Species A. (n.sp..) 428 L.luteilabris 141 L.clunipes 114 L.appendiculata 83 L.fungicola 76 C.nigra 28 L.pseudonivalis 14 L.talparum 11 L.parapusio 4 L.pullula 1 L.heteroneura 1 L.caenosa 1 L.oldenbergi 1 S.monilis C.roserii *

TOTAL: 18197

* Collected as adults only. 154. those cases where there is no direct breeding evidence, that is, in those puparia which were either empty, inviable or parasitised. The frequency of occurrence expressed in Table 11 gives an indication of the constancy of those species breeding within the burrows. Only seven of the sixteen species 4L.claviventris, L. bequaerti, L.palmata, C.fimetaria, L.manicata, Species A and L.clunipes) may be regarded as regular burrow inhabitants. It is interesting that although L.luteilabris occurs in ten times greater numbers than L.pseudonivalis yet its constancy in the burrows is practically the same. Similarly, L. appendiculata occurs a few times in relatively large numbers. C.nigra was bred from five tre.pe all deposited in the same month (December/January 1969) and did not occur in any of the previous months of the experimental period.

b. Seasonal Variation in the Numbers of the Inhabitant Species. There are marked seasonal changes in the number of each species in the bait-traps throughout the year. It is possible to discern an annual 155.

TABLT; 11. Frequency of occurrence of species bred from bait traps (the percentage of traps in which puparia occurred).

Total number of Traps = 265

SPECIES VO. OP TRAPS (A C. TR_LPS CATEGORY OCCUPIED

L.claviventris 145 54.7 L.bequaerti 144 54.4 palmata 98 37.0 C.fimetaria 62 23.4 L.manicata 52 19.6 Species A 31 11.7 L.clunipes 30 11.3 L.fungicola 16 6.0 0 L.luteilabris a 3.0 R L.pseudonivalis 6 2.3 C.nipra 5 1.8 L.appendiculata 4 1.5 L.talparum 2 0.75 VR L,parapusio 2 0.75 Via Ii.caenosa 1 0.4 Vt L.oldenbergi 1 0.4 VR L.pullula 1 0.4 ti L.heteroneura 1 (?.4 VR

Key to categories P, Predominant in over 25'X, of traps C, Common in over 10 - 254ii of traps 0, Occasional in over 5 - of traps Rare in over 1 - of traps VR, Very rare in less than 3.!: of traps 156. cycle in the burrow community, as the maximum numbers and the breeding habits of the various species undergo distinct fluctuations. L.claviventris, which is the numerically predominant species of the burrow fauna, attains its maximum numbers in the autumn from August to October (Table 12 and Figure 55). It undergoes a rapid decline in the winter, and from October to April there is no significant breeding. L. bequaerti, the second most abundant species, also reaches its peak numbers in August to October, but it apparently breeds continuously throughout the winter, although at a very low rate, when it forms the dominant winter species. E.palmata never forms a numerically dominant proportion of the population (Table 13), the timing of its occurrence and breeding maxima closely parallel those of L. claviventris. It reaches maximum abundance in the late summer and early autumn (July to September), with negligible breeding from November to April. C.fimetaria occurs regularly in the bait- traps. The total numbers of C.fimetaria are relatively low, but it breAs throughout the winter,

TABLE 12

SEASONAL CHANGES IN THE PERCENTAGE or THE TOTAL PUPARIA OF THE FIVE MOST ABUNDANT SPECIES (a - e) IN TO BAIT-1gAPS OVfR TWO SEASONS.

1967 1 1968 I I I 1969 PERIODS 6/7 i7/8 8/9 9/10;10/11 11/121 12/1 1/2 :1313/4 4/5 16/7 7/8 !0/9 9/10 10/11 11/12 12/1

Species a. Total puparia 2.8 i6.2 21.4 19.5 0.04 0.03 0.03 2.7 1.3 14.8 17.7 19 0.3 9151

Species b. Total puparia 4.6 2.8 22.7 16.8 0.8 J • 2.7 0.5 1.3 0.3 0.9 8.4 10.7 5.7 13.2 6.5 0.03 0.5 7007

Species c.

Total puparia 0.3 4.5 21.1 5.3 0.8 0.09 1.0 0.09 16.8 26.6 13.7 5.6 3.9 0.09 0.09 1070 TABLE 12 continued

SEASONAL CHANGES IN THE PERCENTAGE OF THE TOTAL PUPLRIA, etc.

1967 PERIODS 1968 11969 6/7 7/8 ;/9- 9/110/11 11/12 12/1 1/2 2/3 3/4 4/5 6/7 7/8 18/9 9/10 10/11 11/12 112/1

Species d.

Total puparia 0.6 2.3 4.6 20 11.7 2.3 0.4 0.3 2.9 1.0 0.4 12.3 15.4 4.0 6.5 3.3 11.5 520

Species e.

Total puparia 0.2 1.3 11.1 0.4 0.2 2.1 2.5 1.1 0.9 - 3.8 16.2 13.7 5.9 7.8 12.4 - 20.2 524

NOTE: Peak percentage underlined. a : L. CLAVIVENTRIS; b : L. BEQUAERTI: c : L. PALMATE!;

d : C. FIMETARIA; e : L. MANICATA. TABLE 13

SEASONAL CHANGES IN THE BURROW FAUNA: THE VARIATION IN NUHBERS OF PUPARIA COLLECTED FOR EACH OF TEN SPECIES THROUGHOUT THE EXPERIMENTAL PERIOD.

I 1967 i 1968 1 I PERIOD 6/7 i 7/8 8/9 9/10 10/11 11/12 12/1 1/2 2/3 L

L. claviventris 261 , 622 1956 17C4 4 - 1 3 _

L. bequaerti 320 193 1589 1175 62 112 190 36 89

L. palmata 3 48 226 57 9 - 1 - -

C. fimetaria 3 12 4 24 104 61 12 2 4 15

L. manicata 1 7 58 2 1 11 13 6 5

L. clunipes _.....42 17 13 - - - - 1 - L. (species A) n. sp. 239 109 78 13 - - - - -

L. fungicola 4 32 4 5 - - - - -

L. luteilabris - 38 t 45 ------

L. appendiculata - - ' 32 1 - - - - -

NOTE: Peak numbers underlined.

TABLE 13 continued

SEASONAL CHANGES IN THE BURROW FAUNA, etc.

1968 1969 PERIOD 3/4 4/5 6/7 7/8 8/9 c,'/10 110/11 f 11/12 , 12/1'

L. claviventris 3 243 163 1357 1617 1099 28

L. bequaerti 24 60 R 590 i 752 400 924 457 2 32

L. palmata 11 1 178 I 285 147 60 42 1

C. fimetaria 5 2 i 64 80 21 34 17 60

L. manicata 20 85 72 31 41 65 106

L. clunipes 1 3 27 4 6

L. (species A) n. sp. 1 11 2

L. fungicola 30 1

L. luteilabris 8

L. appendiculata

NOTE: Peak numbers underlined. 161. declines in numbers in the spring and summer (April to early July), and, like the three other species, reaches a maximum in the autumn (August to October); when it forms a high proportion of the burrow fauna from late October through to January. L.manicata is a winter-breeding species although it appears regularly throughout the year (Table 12 , Figure 55), except in March to April. The population fluctuations for L.manicata are more erratic, with peaks occurring in June/July, August/September and even December and January. L.clunipes and Species A were collected most abundantly in the summer (Table 13) in June and July, their numbers then decline rapidly, and they do not occur in the bait traps in the winter. The occurrence of L.funpicola, Lauteilabris and L.appendiculata is too sporadic for useful discussion (Table 13). Sphaerocerid adults tend to have a peak of abundance in the spring (Richards 1930). But only in one species (I,.claviventris) in the bait- traps is the number of puparia markedly increased 162.

in May (Table 13). It is sugested that this species overwinters in the burrows in the adult stage, and in the spring it is immediately able to take advantage of milder conditions to resume breeding in April, so that large numbers of puparia appear in the bait-traps at the end of ray. Con- versely the effect of the milder conditions on L. bequaerti, which probably overwinters in the pupal as well as the adult stages, is a sudden rise in the rate of emergence. The efiect of the breeding of these spring-emerging adults is not registered in the bait-traps until June and July. The peaks of abundance recorded by Richards (1930) in the spring are probably the result of the resumed activity of those species which overwintered as adults, combined with the effect of an overall increase in the reproductive rate. freeman (1945) records that there is an increased number of Sphaerocerid adults in the upper layers of the atmosphere in hay; this may represent a period of maximum dispersal activity when the overwintering adults become active in a quest for new breeding sites. 163.

In as much as the evidence provided by the suction traps at Silwood Park, may be a true indication of the flight activity of Sphaerocerids, these five dominant rabbit-burrow species do not take part in active flight from April to October (see Section III). Throughout the five year sampling period, only one individual of L.claviventris and one of L.bequaerti were collected in the trap at 4ft.; two specimens of I.palmata were caught and none of C.fimetaria, and only eight specimens of L.manicata were collected on separate occasions from June to August. The open grassland habitat in which the suction traps at Silwood Park were situated (see map in Figure 53) may account for the absence of these predominantly woodland species in the sample material. Another factor which may have to be considered is that these species have become pro- gressively specialised to the burrow micro-habitat so that their wing musculature no longer retains the power for long active flight. The breeding patterns of these five species (L.claviventris; L.bequaerti; L.palmata; 164.

C.fimetaria and L.manicata) are essentially similar (Figure 55). Each species tends to be more abundant in the bait-traps in the late summer and early autumn. There is concrete evidence that three of the species (L.bequaerti; C.fimetaria and L.manicata) continue to breed throughout the winter months, although at a greatly reduced rate. A discussion of the breeding habits of all five species, as revealed by these data, is necessarily hampered, in that the extraction process selected for one particular phase of the life cycle, i.e. the puparium. It may be, that during the colder months from October to Yarch, the life cycle was so extended in its duration, the majority of larvae in the bait had not pupated when the trap was collected, and were not therefore collected from the bait. (The variation in the duration of development throughout the year has been dealt with in 4d of this section). It cannot be said that the species which were collected in the bait-traps, are necessarily typical rabbit burrow species; nor that the numbers in which they were collected, represent 165. their condition relative to each other in the natural state. The provision of a particular bait introduces an element of selection (as has been mentioned in the introduction to this section) and their occurrence in this particular habitat depends upon the availability of other micro- habitats to them. Some Sphaerocerid species show particular habitat preferences: e.g. L.parapusio is most often -.!ound on rotten fungi in woods, and L.pullula is associated with small mammal runs in grass; but this does not necessarily imply a habitat restriction. Both these species have been collected and reared from other habitats (see Section II). Thus it is, that a species may be induced to breed in a number of places once certain basic conditions have been obtained. A species which has an apparent peak of abundance in one micro-habitat, may have a different peak of abundance in R different habitat earlier or later in the season. The peaks of abundance and population totals which are demonstrated by such species as L.palmata, C.fimetaria and L.manicata, in the burrow 166.

bait-traps, are relative, dependent on the availability of other habitats to which they may be adapted. Their presence in the bait-traps may represent an "overspill" situation. On the inter-specific level it is often the case that species which appear to co-exist in the same micro-habitat exhibit a succession of dominance, so that the maximum numbers of a definite stage in the life cycle of each species do not coincide, and thus avoid direct competition for available foodstuffs and breeding sites. The maximum numbers of each species follow on from one another throughout the year. A process known as cyclic isolation (Allee et al. 1949). The impetus for this cyclical process relies on the fact that each species requires a slightly different set of conditions for breeding. So that as the micro-climatic conditions change and the breedinp; substrate alters in its character- istics, the micro-habitat becomes available for exploitation by a different set of species. This system has been found at work in the micro-habitat of the cow-pat. Both Hammer (1941) 167.

and Laurence (1954, 1955) found a seasonal succession of potentially competitive groups amongst the Sphaeroceridae associated with cow-pats. They were able to distinguish between those species that have their peak of abundance as larvae and adults in the winter (certain Copromyza species); those that achieve their maxima in spring and autumn; and those that reach a maximum in the summer (some Limosina species). Hackman's work (1963a) on adult flies in vole burrows, indicates a similar succession of related species. In the Sphaeroceridae there is apparently no great distinction between the habitat requirements of the adults and larvae. Richards (1930) states that the adults are found in constant association with the decayin organic matter which forms the larval foodstuff. It may be expected, therefore, that the period when the greatest numbers of adults appear in the field, in association with a particular micro-habitat (sucA. as cow-pats, mammalian burrows or rotten fungi), is also the period of maximum breeding, when the greatest number of eggs and larvae will be found. 168.

On the available data it is not possible to demonstrate a cyclical process within the species collected from the rabbit burrow bait-traps, except that some species do not appear to breed in the winter, and may possibly be attracted to other micro-habitats as conditions in the rabbit-burrows change.

c. Variation in the Sex-ratio. The total number of individuals of each sex and the sex-ratios derived for each species from the breeding records are given in Table 14. At emergence the numbers are approximately equal. The collection of adult flies at the rabbit burrow entrance and from other habitats did not yield sufficient data for a quantitative assessment of sex-ratios. However, from my own collecting data and from information provided by Richards (1930), Goddard (1938) and various other authors (see Section II), the male and female of the five most abundant burrow-tunnel species (i.e. those occurring in the bait-traps) have been collected in most months of the year. Richards (1930) states that the proportions of the sexes 169,

‘22-1.331t; 14. Vidt125.T I ON IN T1-I S J.3:1*-Ri.i.TI 0 Urz.' DS BRED

PROIVi BA I " PLAC V3D Ii AB.IT BURRO'S .

"1 ES MALES FilMI,WSS SEX7RATIO

L.manicata 235 193 121.7 I. fungi c o la 31 27 114.8 C.fimetaria 213 204 109.8 I . claviventris 3628 3687 98.4 L.luteilabris 4L 49 97.9 L.bequaerti 2532 2865 88.4 I.(Species A) n.sp. 132 168 78.6 h.palmata 262 334 78.5 ii.clunipes 41 60 68.3 L.appendiculata 24 38 63.2 170. are approximately the same for a given species in each month of the year in which the fly occurs.

d. Seasonal Variation in the Duration of Development. The duration of development has been measured, for convenience, as that interval in days between the deposition of the bait in the burrow and the emergence of the adult flies in the outside insectary. This is only an arbitrary measurement, since it cannot be assumed that all the flies lay their eggs in the bait at the same time. The number of empty puparia found each month, (i.e. the puparia of those flies whose life- cycle was completed within 28 days, when their duration of development was at its minimum) have not been included in the data in Table 15 and lg. However, when the numbers of empty puparia of all species approach 20% of the total puparial count this has been indicated. (The high percentage at the end of March and beginning of April probably represents the suddesi emergence of flies in the first warm days of spring). TABLE 15 SEASONAL VARIATION IN THE DURATION OF DEVELOPMENT: THE NUMBER OF FLIES 'EMERGING IN SEVEN WEEKLY PERIODS 40 ee .. se oe oe se ee ee

a - L. claviventris. b - L. bequaerti. c - other species.

PERIOD SPECIES DAYS AFTER. DEPOSITION OF BAIT TOTAL FLIES 29 - 35 36 - 42 43 - 491 50 - 56 57 - 63 64 - 70

1967 6/7 a NUMBER OF 63 55 16 FLIES 143

% OF TOTAL 2.1 44.1 38.5 11.2 2.1 2.1

b NUMBER OF I 127 47 16 FLIES I 5 196

% OF TOTAL 64.P. 24 i P). 9 2.6

c NUMBER OF 21 83 40 60 16 224 FLIES 4

% OF TOTAL I 9.4 37.1 17.9 26.8 ( 7.1

TABLE 15 contd DAYS AFTER DEPOSITION OF BAIT

TOTAL 1967 SPECIES 29 - 35 36 - 42 43 - 49 50 - 56 57 - 63 64 - 70 71+ FLIES 7/6 . 1: a NUMBER OF 40 198 6 244 FLIES

CZ OF TOTAL 16.4 81.2 2.5

b ;NUMBER OF 13 64 IFLIES 77

17. OF TOTAL 16.9 83.1

NUMBER OF 96 62 FLIES 15 3 176

Z OF TOTAL 54.61 35.2 8.5 TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT TOTAL FLIES 29 - 35 3 - 42 i43 - 49 150 - 56 57 - 63 64-70 71+

1967 a NUMBER OF 5 598 451 I 320 107 2 1483 8/9 :FLIES

% OF TOTAL 40.3 I 30.4 21.6 7.2

b NUIABER OF. 3 229 f 770 312 23 22 FLIES 1367

70 OF TOTAL 16.3 1 56.3 I 22.8 2 1.6

c NUMBER OF 20 166 4 144 'FLIES 44 35 14 409

Z OF TOTAL 4.9 40.6 35.2 10.8 I 8.6 3.4 TABLE 15 ccntinued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT

29- 35 26 - 42 43 - 49 50 - 56 57 - 63 64 - 70171+ TOTAL FLIES 1967 a NUMBER OF 322 116 i 89 93 307 33 1172 1122 7115 FLIES

% OF TOTAL 28.9 10.3 7.9 8.3 27.4 2.9 15.3

b NUMBER OF 77 42 17 184 280 137 FLIES 345 1082

% OF TOTAL 7.6 i 3.9 1.6 17 25.9 12.7 131.9

NUMBER OF FLIES 9 49 42 19 9 16 134

% OF TOTAL 6.7 36.6 I 31.3 1 14.2 i 6.7 14.5 TABLE 15 continued

PERIOD SPECIES DAYS AETNA DEPOSITION OF BAIT 29- 35 36 - 42 43 - 49 50- 56 57-63 64 - 70 TOTAL FLIES

1967 10/11 a NUMBER OF 1 2 3 FLIES

b NUMBER OF! FLIES 4 11 29 8 52

r OF TOTAL 7.7 21.2 55.8 i 15.4

NUMBER OF: FLIES 28 5 3 51 % OF TOTAL 54.9 9.8 15.7 13.7 5.9

1967 b NUMBER OF' 30 9 39 11/12 FLIES 1 % OF TOTAL 75.9 23.1

c NUMBER OF; FLIES 4 4 TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT TOTAL 29 - 35 36 - 42 143 - 49 150 - 56 157 - 63 164 - 701 71+ PLIES

1968 0717 b NUMBER OF FLIES 3 55 i 62

% OF TOTAL 88.71

c NUMBER OF FLIES 11 3 1 14

1968 1/2 b NUMBER OF FLIES 24 1 14 1 39

% OF TOTAL 61.51 35.91

c NUMBER OF FLIES 1 2 1 4 1 8

TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT TOTAL 29 - 35 36 - 421 43 - 49 50 - 56 57 - 631 64 - 70 71+ FLIES 1 1968 2/3 NUMBER OF 1 FLIES 1 3 4 13 20

7. OF TOTAL 65

NUMBER OF FLIES 11 11

1968 J74 + a NUMBER OF _ _ _ - FLIES 3 _ - 3

b NUMBER OF FLIES - - 6 - - - - 6

c NUMBER OF FLIES - - - 1 1 - - 2 TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT TOTAL 29 - 35 136 - 42 1 43 - 49 50 - 56 57 - 63 64 - 70 71+ FLIES 1 1

1968 NUMBER OF 751 a 6 6 FLIES 31 143

OF TOTAL' 4.1 4.1 33.1 c8.8

b NUMBER OF 2 FLIES 1 7 8 13

Z OF TOTAL! 44.4

c NUMBER OF I 12 FLIES 5 17 TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT

, TOTAL 29 - 35( 36 - .2 1 43 - 49 1 50 -- 56 157 --- 63 64 - 701 71+ FLIES

1968 6/7 a NUMBER OF 26 1 29 1 FLIES 45 100

b NUMBER OF 141 160 f 50 FLIES 354

% OF TOTAL 39.8 45.2 14.1

c NUMBER OF PLIES 38 1 61 2 - I 101 1 % OF TOTAL 37.6 60.4 1 TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT TOTAL 29-35 - 42 43 - 49 50 - 56 57 - 63 64 - 70i 71+ !FLIES

1963 7/8 a NUMBER OF 7 272 525 41 845 FLIES

% OF TOTAL 32.2 62. 4.9

NUMBER OF 212 274 14 500 FLIES

7. OF TOTAL - 42.4 54.8 2.8

c NUMBER OF FLITS 18 206 33 1 258

% OF TOTAL 7.0 •79.9 12.8 1 - TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT TOTAL 29- 35 36 - 421 43 - 49 50 - 56 57 - 63 164 70 71+ FLIES

1968 a NUtSER OF 25 FLIES 408 863 i 217 1513

7. OF TOTAL1 1.7 27 57 14.3'

b NUMBER OF 52 160 180 6 398 FLIES

Z. OF TOTALI 13.1 40.3 45.3 1.5

NU/53ER OF 42 170 41 253 FLIES

Z OF TOTA 16.61 67.2 16.2

TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT TOTAL 29- 35 36 - 42 143 - 49 150 - 56 1 57 - 63 1 64 - 70 71+ FLIES

1968 a NUMBER OF 215 723 4 FLIES 106 6 1 1083

% OF TOTAL 19.9 66.8 9.3 2.6

b NUMBER OF 190 FLIES 516 97 35 5 i 3 2 828

Z OF TOTAL 23 62.3 11.7 4.2 0.6

c NUMBER OF 6 45 22 73 FLIES

OF TOTAL 8.2 I 61.7 30.1

TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT TOTAL 29 - 35 36 - 42 143 - 49 50 - 56 1 57 - 63 64 - 70 171+

1968 10/11 a NUMBER OF 2 6 FLIES 9 17

b NUMBER OF FLIES 9 89 113 64 275

Z OF TOTAL 32.4 41.1 23.3

c NUMBER OF .FLIES 29 37 57 8 2 133

% OF TOTAL, 21.8 27.8 1 42.9 6.0 TABLE 15 continued

PERIOD SPECIES DAYS AFTER DEPOSITION OF BAIT TOTAL 29- 35 36-42 43 - 49 50 - 56 57 - 63 164 - 70 171+ FLIES

1968 11712 b NUMBER OF 2 FLIES

NUMBER OF 11 7 1P FLIES

% OF TOTAL 61.1 33.9

1969 12/1 b NUMBER OF FLIES 23 28

NUMBER OF I FLIES 8 57 23 i 71 159 % OF TOTAL] 35.9 14.5 44.8

NOTE * = 19.7% of all puparia collected were empty FJ a) + = 45% TABLE 16

SEASONAL VARIATION IN THE DURATION OF DEVELOPMENT OF C. PIMFTARIA: THE NUMBER OF FLIES EMERGING IN SEVEN WEEKLY PERIODS FRON BAIT DEPOSITED THROUGHOUT THE YEAR.

DAYS AFTER DEPOSITION OF BAIT.

PERIOD 29 - 35 36 - 42 43 -• 49 50 - 56 57 - 63 64 - 70 71+

8/9 1967 4 4 2 - - - 9/10 1967 4 41 17 2 - - - 10/11 1967 - 28 5 80 7 3 1/2 1968 - - - - - 4 2/3 1968 - - - 6 - 7/8 E68 1 27 8 8/9 1968 73 21 9/10 1963 3 8 - - - _ 10/11 1968 _ 24 5 3 11 /12 1968 - - 10 - 7 - 12/1 1969 40 186.

The records of L.claviventris and L.bequaerti in Table 15 (a and b respectively) have been treated separately. Records for all other species (including C.fimetaria) have been grouped into c. Data for C.fimetaria nas been set oat in Table 16. The agaergence patterns of Troup c in Table 15 show the same general trend as those of a and b. There is a dellnite relation between the season, and lengtn of the life cycle the flies take longest to emerge between 'jThvember and harch, and the shortest developmental period is found in June, July and August. This is represented diagram- atically in Figure 56, where only those monthly periods in which at least 100 flies emerged have been included. As Laurence (1955) showed in the succession of e:-h,lyin-,:r7 by diferent species of Sphaeroceridae on cow-pats, the ageiry of the bait in the rabbit burrow may result in a similar succession; the females responding as the consistency, moisture content, and attractant qualities of tne rotten grass alters. The emergence patterns mi, ht be expected to reflect these e-layin habits of the 187.

parents. However, the emergence records of C. fimetaria (Table 16) are similar to those of Ii. claviventris and L.bequaerti (Table 15) so that, if there is a succession, these three species do not reveal it. Life-history data obtained from laboratory observations on a number of species (see Section II) have shown that life cycles tend to extend from 20 to 30 days at 20°C. The various extensions of the life-cycle shown in these d.ota, might be expected to be a result oi• the fluctuatin6 temperature conditions within the rabbit burrow throughout the year. One species, in brticular, had a greatly extended life-cycle: no flies from the puparia of C.ni7ra collected in mid-January 1969, emerged before April or May 1969. This species was not collected elsewhere, so the possibility that this prolonged pupal stage may be typical, cannot be ruled out. The lack of any definite peak in the emergence dates of flies in September and October 1967 (figure 56) may be due to the fact that the puparia responded in two ways during this climatically 188.

transitional period, when the milder conditions of autumn (October) change to the colder temperatures of November. Plies which emerged within the seventh week are still subject to the autumnal conditions whereas those wnich emerge after eight weeks are respondin to a winter oituation. Sphaerocerids do not ap parently have a winter diapause. Adults of the majority of species have been collected throu,:hout the year, (see Section II) and the puparia of at least three species (Ii.bequaerti, C.fimetaria and L.manicata) were collected in the bait-traps in every month (see Table 13). The extension of the life-cycle, so that the developmental period of the immature stages is prolonged, is not an overwintering device as such, but a response to low temperatures. Laurence (1954 and 1955) recorded that Sphaerocerid larvae collected from cow-pats in Iovember and December, emerged in April, Eay and June. If the temperature at which these larvae were kept was raised, they completed their development in a shorter period of time. Both Rammer (1941) and Hackman (1963a) refer to species with a system of 189.

pupal hibernation. It is probable that by this they mean to imply a situation where the puparia undergo a period of facultative quiescence, mani- fested as prolonged development durin6 the winter, rather than an obligate diapause. I have recorded only one instance of apparent "pupal hibernation" in the Sphaeroceridae: adults from puparia of L.appendiculata collected in a bait-trap deposited in a small malmal run in grass on 11.9.67, emerged on 6.5.68 (an eight month hibernation period). The collection of puparia from the rabbit burrows in every month of the yeer indicates that the female flies of J.J.becuaerti and a.fimetaria are capable of continuous reproduction. However, in a number of traps deposited in the winter months the bait became dried up and useless as an attractant. This can be rearded as an indication of what normally happens to the vegetable refuse in the burrow on which the female flies would lay their eggs. The puparia collected from the winter bait which did not deteriorate in such a manner, could well be a result of the females taking advantage of a suitable medium, rather than giving a normal 190. winter response. The relatively low numbers of puparie collected for each species during the winter, may be the result; of several factors. The majority of egs laid by each female failed to develop because of low temperatures; the medium on which the eggs were laid became unsuitable as a larval food (see above); or a large number of female flies present in the burrows during the winter were in a state of reproductive arrest. A state which has been shown to exist in certain Drosophila species (Diptera: Drosophilidae) by (Jerson and Stalker (1948) and Basden (1954). Female Drosophilids captured in the winter months reproduce much more slowly than those captured at other times of the year, the ovaries of the majority of these over- winterin -,:emales remain in an undeveloped or dormant state until environmental conditions change. (This diapause can be broken in some species by subjectin- the females to higher temperatures in the laboratory). It may be that females of L. claviventris are subject to such an overwintering arrest, and that the high numbers of puparia which suddenly appear in the oait-traps in kiiay (see 191.

Table 13) are the result of the resumption of egg- layin by these overwinterinL; females as soon as environmental conaitions become milder. There is no actual evidence, from this study or from previous work, that Sphaerocerid females have any such system of reproductive diapause. Indeed, Hammer (1941) found that females with mature ovaries of S.pusilia, S.curvipes, L.clunipes and L.lugubris are active in the winter months on cow-pats; and Laurence (1955) observed that both L.silvatica and 0.nitida laid egs in dung in the field from November to March. however, the low numbers of pupsria collected from the rabbit burrow bait-traps from November to parch here, and the fact that only a small proportion of these developed (less tnan 405 in some months) indicz.,tes that either the bulk of the population was still in the larval stae at the time the bait was collected, or that these species reproduce in a different habitat in the winter.

e. The Trappinp- Methods and Species Distribution. It may be, that some Sphaerocerids of the rabbit burrow fauna are ;:got adapted to the precise 192. conditions provided ())- the bait-traps in the burrow tunnel; so that the collection of puparia from the rrait does not necessarily give an indication of the presence or absence of a species. In order to suet some indication of the Sphaerocerid fauna of undisturbed burrows, random collections were made at the burrow entrances throughout the year using a "pooter" (no collections were made at the entrance of those burrows used in tie bait-trap experimehts). fable 17 lists tnose species that were collected as adults at the entrances to rabbit burrows, arranged accordin, to the number of burrows at which they were collected. li.silvatica is a species which has been collected regularly at buJ:row entrances, but not bred from the bait-traps. Goddard (193 ) reared this species on decaying grass in the laboratory, so it is not likely that the bait itself was unsuitable. Richards (1930) records it as a typical woodland species. It is probable that the presence of this species at burrow entrances is due to the immediate proximity of woodland leaf-litter refuse, and not the rabbit burrow situation as such. 193.

TABLT] 17. SZTL;CIES CUILLECTED AT T?..,1.]- .1;.L.TRAIICE- T0 RABMT 3U1-WOWS

SPECIE3S NO. OP MONTHS CATEGORY IN 3URROWS BAIT-TRAPS

L.manicata * 39 1, 2, 4-11. C L.bequaerti * 17 1, 3, 6, 8-10. P L.silvatica 17 6-10. - C.fimetaria 11 1, 2, 4-6, 10. P L.clunipes * 16 1, 2, 5-10. C C.nitida 8 4, 6, 7, 9-11. - L.claviventris* 6 1, 3, 7-9. P L.fenestralis 5 6, 6, 10, 11. - L.moesta 5 1, 9, 10. - C.similis * 5 1, 5. - h.fungico1a * 4 7, 8, 10. 0 L.parapusio 4 1, 6. VR L.fontinalis * 3 4, 8. - L.palmata * 3 1. P h.talparum 2 2, 8. VR L.schmitzi * 2 10. - C.atra 1 8. - L.scutellaris 1 9. L.appendiculata* 1 1. It L.rafilabris 1 11. L.vitripennis 1 10.

* Previously recorded by Richards (1930) from this habitat. Note: Species A, L.luteilabris, C.nigra, L.pseudonivalis, L.heteroneura, Lecaenosa, and L.oldenberpi were bred from the bait-traps but not collected at the burrow entrances. 194.

The next most abundant species which. has not been bred from the bait traps, C.nitida, is also recorded by Richards (1930) as a woodland species, found on dead lea,res and common in dung. Its association with rabbit-burrows in this case is probably equally fortuitous. L.palmata, one of the predominant species in the bait-traps, has been collected only rarely at the entrance to rabbit burrows. In Silwood Park it has been collected frequently from rotting fungi in woods, and on carrion. It seems likely that the boiled grass bait is particularly attract- ive to it as a breeding medium, rather than that the species is especiany associated with rabbit burrows. Richards (1930) described L.claviventris a species occurring on "decaying vegetable matter in shaded places". In Silwood Park it has been collected only rarely as an adult: on rotten fungi in woods, and in association with rabbit burrows. .P.s the dominant member of the bait-trap fauna, L.claviventris is probably attracted primarily by the boiled grass bait, rather than to the rabbit 195.

burrow as an ecological niche. Hackman (1963a) emphasised the short- comings of bait-trapping as a method for the assessment of a naturally occurring population in a particular habitat: the bait tends to attract "certain categories of feeders" and vagrants from outside, which do not necessarily belong to the regular fauna. This hazard may be partially over- come by depositing the same type of bait in other habitats, and coilectinF; the species which are attracted to it. Boiled grass was therefore placed in plastic mesh-cylinders (Figure 1) and adult-traps (Figure 2) in rough grass (small mammal runs etc.) and in woodland. Table 18 gives the species collected or reared from the bait in these traps (listed in alphabetical order). The results expressed in Table 18 have not been assessed quantitatively, so that there is no indication of the relative abundance of the species in the different habitats. levertheless these collecting records do emphasise that certain species (including; the five most abundant burrow species), such as L.bequaerti, L.claviventris, L.fungicola, 196.

TAM 18. JPIIAW.C13RIT);.E COLLLCTD ea inkT7CAID FROh BOILED GRASS BAIT.

SPECIES WODLAND BURROW

L.appendiculata* + + L.bequaerti + + L.caenosa* + + L.claviventris* + + + L.clunipes * + + + L.funvicola * x x + L.heteroneura * x L.luteilabris * + + L.manicata * + x + L.oldenbergi + L.palmata * x x x L.parapusio x + L.pseudonivalis + L.pullula * + x + L. (Species A) n.sp.* + + + C.fimetaria x x + C.nigra + S .pusilla * +

Bred in laboratory on boiled grass. Reared from the deposited bait and collected as adults. x Collected as adults only. 197. h.manicata, L.palmata, L.pullula, Species A and C.fimetaria may be attracted to grass bait whether it be deposited in grassland, woodland or down rabbit burrows. On bait-trap data it is difficult to make a distinction between woodland and grassland species as such. Sphaerocerid adults apparently prefer protected, well-defined micro-habitats, with a particular combination of humidity and temperature. The least that can be deduced from these data is that a species such as L.claviventris is attracted to boiled-grass bait in a number of vegetationally dissimilar habitats, nevertheless this species has been collected sufficiently frequently in woodland for Ricitards (1930) to define it as a woodland species. It is not possible at present to account for the fact that those species most abundant in burrow bait-traps (L.claviventris, L.bequaerti, L.palmata, C.fimetaria, and .6.manicata)- do not occur in the suction trap material in any apprec- iable numbers. These species obviously reach the grassland, at least in low numbers, since they have been collected or reared from bait deposited there.

198.

f. Parasitism. A large number of parasitic Hymenoptera (Chalcidoidea, Proctotrupoidea and Cynipoidea) were reared from puparia of at least six species collected from the bait-traps from May to October. The material is bein identified by G..j. Nixon and J. Quinlan at the BritisA Iduseum U.H.), and at present only generic names have been applied to the specimens. Although specific names have not yet been determined, it appears that there is a limited number of parasite species involved in this instance, which do not exhibit host-specificity. Goddard (1938) reared three specimens of Phaenopria cameroni, Kieft. from the puparia of a Leptoceran species (probably L.vagans), and it can be seen in Table 19 that this genus is common to all the parasitised puparia collected here from the bait-traps. The fluctuations in the numbers of parasitised puparia obtained for each species is demonstrated in Table 20. It appears that the puparia are only liable to attack by parasites from May to October, and the greatest percentage of puparia are affected in June, July and August.

TABLE ' 19

PARASITE/HOST ASSOCIATIONS

ROST SPECIES PARASITES

ASRMEADOPRIA sp. KLFIDOTOMA sp. PHAENOPRIA sp. SPALANGIA sp. TRICHOPRIA sp. (proctotrupoidea) (Cynipoidea) (proctotrupoidea) (;lisl.cidoidea) (Proctotrupoidea)

L. claviventris L. bequaerti L. palmata group C. fimetaria Species A L. fungicola )

TABLE 20 FLUCTUATIONS IN PARASITE NUMBERS

HOST SPECIES MONTH 1967 1968 6/7 7/8 3/9 9/10 4/5 6/7 7/8 8/9 9/10

TOTAL NO. OF PUPARIA 261 622 1956 1784 243 163 1357 1617 1099 L. claviventris TOTAL NO. PARASITISED 21 36 49 5 5 99 155 16 45

% PARASITISED 7.7 5.8 2.5 0.3 12.1 60.7 11.4 1.0 4.1

TOTAL NO. L. bequaerti OF PUPARIA 320 193 15 89 1175 I 60 590 752 400 924 TOTAL NO. PARASITISED 99 9 11 0 8 90 50 3 2 % PARASITISED 30.9 4.7 0.7 13.3 15.2 6.6 0.75 0.2

17,jTAL NO. OF PUPARIA 46 72 297 59 24 290 261 179 101 L. palmata grout TOTAL NO. PARASITISED 19 36 23 1 4 147 78 8 ' 3 PARASITISED 4.1 50 7.5 50 23.7 4.5 I 4.7 TABLE 20 Continued

FLUCTUATIONS IN PARASITE NUMBERS

HOST SPECIES MONTH 1967 1968 Tir 1 7/8 8/9 1- 9/10 4/5 6/7 7/0 3/9 9/10

C. fimetaria TOTAL NO. OF PUPARIA 3 12 24 15 64 80 21

TOTAL NO. PARASITISED 4 6 3 13 3 2

% PARASITISED 33.3 9.5

Species A TOTAL NO. L. fungicola OF PUPARIA 423 141 82 23 41 1 9

TOTAL NO. PARASITISED 10 12 5 .1 5 1

7 PARASITISED 4.1 0.5 6.1 1 4.3 12.2 1

NOTE Peak percentages underlined. 202.

g. Laboratory Observations on the Burrow fauna. The following bait-trap species were bred successfully in the labortory: L.claviventris, h.manicata, Species A, L.luteilabris, L.clunipes, L.aPpendiculata, L.fungicola, L.parapusio, I.pullula, L.heteroneura, L.caenosa (see Section II for details). These laboatory investigations provided an insight into the breedin(f potential of these species, a fact which could be related to their occurrence in the bait-traps. Nated females of liJ.caenosa were found to lay large numbers of eggs in a short period of time on boiled-grass media, a fact which has been well documented by Predeen and Taylor (1964), and yet only one puparium was collected in the bait-traps throughout the entire experimental period. Simil- arly both h.pullula and L.parapusio appear in the bait-traps on only a few occasions (see Table 2). In the 1.- oratory these two species were found to be parthenogenetic, each virgin female laying; large numbers of eggs which give rise to the next all-female generation. It is interesting that 203. species in which every individual of the population is capable of reproduction, and where there is an increased reproductive efficiency, did not appar- entJy take advantage of available egg-laying material and occurred in the "bait" in such in- significant numbers. It may be, that the con- diti,ns of the bait-traps in the rabbit burrows do not fully satisfy their habitat requirements. L.pullula was bred in large numbers from boiled- grass bait deposited in grassland, and L.parapusio from rotten fungi collected in woodland. Repeated attempts to breed ii.bequaerti and C.fimetaria under laboratory conditions failed, although the adult flies survived for long periods of time on various media (see Section II). It may be that some behavioural reauisite was not satisfied in the laboratory, such as prolonged flight activity after emergence. On no occasion was L.bequaerti observed in copula, and eggs were obtained on only a few occasions from wild-caught individuals. C.fimetaria was observed in copula on one occasion, but no eggs were laid. 204.

SECTION V GENERAL DISCUSSION.

The diversity of habitat situations in Silwood Park is exemplified by the fact that seventy three of the hundred or so British species of Sphaeroceridae were collected in or around the field-station. A number of these species were collected only rarely, nevertheless their presence is of interest. In the genus Sphaerocera one species, S. scabricula (14)1 would not appear to be as rare as was previously supposed (Richards, 1930 p. 318). This species was collected regularly at Silwood Park from decaying grass in the tip F in Figure 53, and was identified in the suction trap material. In the genus Copromyza, C.nigra (8) is an interesting record. A dung-frequenting species, Richards (1930, p. 312) records it as confined to N. and W. England, particularly common at high altitudes. In the genus Leptocera, L.oldenbergi (22) was recorded on

1The figure in brackets after the name of each species is a reference to its position in the text in Section II. 205.

only one occasion, and its intermittent occurrence would appear to be a general feature of its distribution in the British Isles (Rich rds, 1930 p. 284). I.7aricornis (24), I.lutosa (25), L. limosa (26) and L.7osterae (31) were collected in the suction traps at Silwood Park, but their usual habitats are estuarine mud and refuse on the sea shore (Richards, 1930). L.spinosa (58) was described by Collin (1930) from a single known male, and the female of this species is unknown (Richards, 1930 p. 303). Constancy of habitats it difficult to establish in the Sphaeroceridae (Richards, 1930). Most of the species in Silwood Park have been collected at a number of different micro-habitats, and the results discussed in Section IV (4e) and outlined in Table 18 demonstrate that in any assessment of the habitats of the Sphaeroceridae it is habitat preferences rather than habitat restrictions which must be considered. Thus it is, that species such as L.claviventris and L.parapusio were collected regularly in woodland, occasionally in grassland, and only rarely in the suction traps which were 206.

sampling an essentially grassland community. The breeding potential of those species studied in the laboratory is essentially similar both in the numbers of eggs produced (except in the case of L.caenosa), and the duration of the life cycle. In the field it has been seen that flies continue to breed throughout the year, but the time interval between the formation of the puparium and the emergence of the adult, is greatly prolonged in the winter months during a period of facultative quiescence. There is a tendency for virgin females to lay numbers of infertile eggs (L.claviventris and L.caenosa), and two species, L.pullula and L.parapusio have a system of facultative thelytoky. It is probable that parthenogenesis Accurs in at least two other acalypterate families: the Chamaemyidae (Sturtevant, 1923) and the Droso- philidae (Stalker, 1954). In Drosophila partheno- genetica, as in Lonchoptera furcata (Lonchopteridae) (Stalker, 1956) meiosis does occur, but the nucleus is reconstituted by an automictic process, when two of the four haploid meiotic products fuse. It is possible that such a system is at work in the 207.

ovarian nurse cells of L.pullula and L.parapusio, and the ease with which these species can be bred in the laboratory, would make ',:aem ideal subjects for a genetical and cytological study. The eggs and puparia of Sphaerocerids exhibit great morphological variety. Hammer (1941) observed the egg-laying behaviour of female Sphaer- ocerids on cow-pats, and noted that the eggs of L. lugubris and L.pusilla were pushed vertically into the dung so that only the long flanges, or extensions of the hatching lines, were exposed. Hinton's work on the respiratory plastron of insect eggs, particularly those of Diptera (1961) indicates that the complex of papillae and chorionic reticulations of Sphaerocerid eggs enable respiration to continue in a waterlogged substrate. Sphaerocerid eggs tend to be laid in damp, potentially waterlogged habitats, and there would seem to be a direct relation between structure and function in this case. Laboratory observations on the immature stages of the Sphaeroceridae confirm that the larvae respire chiefly through the posterior spiracles, which in Leptocera species are surrounded by a 208.

rosette of hydrophobic hairs. larvae on nutrient agar feed completely submerged with only the posterior spiracular processes projecting. The anterior prothoracic spiracles are pliable unsclerotised structures, which on the formation of the puparium become heavily sclerotised and stiff. Puparia which are submerged in the substrate, so that the prothoracic spiracles are covered, fail to develope. The form of the anterior prothoracic spiracles in the puparia of Sphaeroceridae provide definite specific features. The Sphaeroceridae are a predominantly terrestrial group, nevertheless the abundance of species (66) identified from the suction-trap material is striking. The exact role of flight activity in the distribution of the Sphaeroceridae, cannot be assessed until adequate data exists of fluctuations in the ground populations. The investigations on the rabbit burrow fauna demonstrate that most species are capable of continuous rei.Jduction, and that their presence in a particular habitat is not necessarily fixed, but depends on the availability of other habitats to them. 209.

SECTION VI .LCKNOWLTIDG7Q.ENTS.

I should like to express my gratitude and thanks to Professor 0.W. Richards and Professor T.R.E. Southwood for the provision of facilities at Silwood Park, the field station of- Imperial College, during the course of this work. I should like to thank my supervisor, Professor 0.W. Richards, for his help and advice, and for the loan of some of his valuable reprints. I am indebted to the academic and technical staff at the field station: particularly to Professor T.R.E. Southwood, for permission to use material from the suction-traps; to the late J.W. Siddorn, for his advice on drawing techniques; to Yrs. 1i. van Emden, for translations from German; to H. Devitt, for takin the photographs; to E. Green, for identification of the fungi; and to L. Warner, for showing me the badger sets. I should like to thank the staff of the British Museum (N.H.) and the Hope Department of Entomology (Oxford) for allowing me access to their collections; with especial thanks to G.E.J. Nixon 210.

and J. Quinlan of the British Museum, who kindly identified the Hymenopteran parasites. I should like to acknowledge the financial assistance of the Science Reserch Council, who awarded me a State Studentship from 1965 to 1968. Finally, my grateful thanks are due to Mrs. G. Sevastopulo who did the typing. 211.

SECTION VII SUIAYARY.

1. Seventy three species of Sphaeroceridae (5 Sphaerocera, 14 - Copromyza, 54 - Leptocera) were identified from material collected in and around Silwood Park. 2. Various field-collecting techniques, and methods employed in the laboratory fur breeding and observ- ing the flies are described. 3. Habitat data and monthly records are cited for all the species collected. The life-histories of a number of species were recorded under laboratory conditions, and the immature stages are figured and described. A mechanism of facultative thelytoky was confirmed in two parthenogenic species: L. pullula and L.parapusio. 4. A new species, denoted as L.(Species A) n. sp., remarkably similar to L.fungicola was collected and reared. Its mature and immature stages are described and figured. 5. The morphology of the eggs and puparia of Sphaerrceridae have definite specific features, and it is hoped to produce a specific key to puparia. 212.

A generic key to the puparia of the 3 British genera has been compiled from material described here, and from a number of other sources. 6. Four species: L.clunipes, L.curvinervis, L.moesta and S.pusilla predominated in a total of sixty six species, identified from material collected by means of suction traps, operated at Silwood Park from April to October for five successive years (1961 - 1965). 7. The flight activity of these four species was fairly uniform for each month of the six month period, and at no time was it apparent that either males or females were more abundant in the aerial fauna. 8. A number of species collected in the vicinity of the traps were notably absent from the suction trap material (L.fenestralis form nivalis; L. claviventris; L.becuaerti; L.palmata; L.fimetaria; L.manicata and L.parapusio). 9. It is not possible to assess the relation between the flight activity of Sphaerocerids (as indicated by suction trap catches) and the weather, until comprable quantitative data exists of fluctuations in the ground populations. 213.

10. The Sphaerocerid fauna of twenty rabbit burrows, located in predominantly woodland areas of Silwood Park, was studied over an eighteen month period by means of a method of "bait-trapping". 11. Boiled grass "bait" was used as an attractant and a breeding medium for the flies. No adults were collected directly, but were bred out from the puparia which were extracted from the "bait". A total of eighteen species were reared in this way, the predominating species were L.claviventris, L. bequaerti, L.palmata, C.fimetaria and L.manicata. 12. Breeding occurred in the bait throughout the year, although in the colder months from November to March the duration of development was greatly prolonged. 13. Emphasis was placed on the hazards of using "bait" in the assessment of a naturally occurring insect population. The deposition of boiled grass "bait" in a number of other micro-habitats, demonstrated that species such as L.palmata and L. claviventris are not necessarily confined to rabbit- burrows as such, but may be attracted into the burrow from other habitats by the presence of the bait. 214.

14. On this and other evidence it is apparent that the Sphaeroceridae are subject to a system of habitat preference rather than habitat restriction. 15. Parasitic Hymenoptera (Chalcidoidea, Procto- trupoidea and Cynipoidea) reared from Sphaerocerid puparia do not apparently exhibit any host-specificity. 215.

SECTION VIII BIBLIOGRAPHY.

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SECTION IX FIGURES 4 - 56.

FIGURA 4.

S.MONILIS

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes.

Note: the scale indicator in Figures 4 - 51 is in mm.

I.0

s.0

g •zct 2 3 3 .

GURE 5.

S , Contd .

D. Egp.. 234%

0 • I 235.

IiIGURE 6.

S.PUSILLA

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes.

A s

0.5

C 237.

FIGURE 7.

S.PUSIL1A, Contd.

D. Third instar larva: right lateral view. E. Detail of third instar larva: posterior spiracular plate.

239.

FIGURE 8:

S-.SCABRICULA

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes.

40.

0-5

0•I 241. wIGURE 9.

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes.

A B 24-2.

...... • .

. • • • ...... • . .

...... , „

C 243.

PIGILRE 10.

C.YIMETARIA, Contd.

D. Third instar larva: right lateral view. E. Detail of third instar larva: segments and II, showing cephalopharyngeal skeleton and anterior spiracular processes. P. Detail of third instar larve: posterior spiracular processes. 7 0 kt

Nm 245.

12IGURE 11.

C.NIGRA

Puparium (detail): anterior spiracular processes. a 246- I 1 247.

PIGUtZE 12.

Il.?ONTIhALIS

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes.

24-8.

A B

0-5

r 249.

PIGURI3 13.

L.CAEJOSA

A. Egg: dorsal view. B. Egg: lateral view. 2.50. 251.

2IGURtIli 14.

L.OLDENBBAGI

A. Puparium: dorsal view. B. Puparium: ventral view. cn

'"' • • • • " ' • • " .. 253.

FIGURE 15.

L.OLDENBERGI, Contd.

C. Detail of puparium: anterior spiracular processes. D. Detail of puparium: cephalopharyngeal skeleton of third instar larva. U n

0 255.

rIGURE 16.

L.VENESTRALIS

A. Puparium: ventral view. B. Puparium: dorsal view. C. Detail of puparium: anterior spiracular processes.

A B 256.

0.5

0.1 257.

17.

L.PEITESTRALIS FORM NIVALIS

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes.

258. A 13

0.5

0.1 259.

FIGURE 18.

L.BEQUAERTI

A. EEE: left lateral view. 260.

0 • I 261.

FIGURE 19.

L.BEWAERTI, Contd.

B. Egg: right lateral view, with larva emerging.

C. Detail of egg chorionic reticulation. 262.

1 263.

FIGURE 20.

I.PUNGICUA.

Egg: lateral view.

s I O 265.

FiGUR2 21.

L.MIRABILIS

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes. A B 266.

C 267.

10IGORE 22.

L.APPENDICULATA

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes. A 13 268.

0.5

0•1 269.

FIGURE 23.

L.APPENDICULATA, Contd.

D. Third instar larva: right lateral view. E. Detail of third instar larva: cephalopharyngeal skeleton. 2. Detail of third instar larva posterior spiracular process. Vt 0 •

......

IL 271.

FIGURE 24.

L.MOESTA.

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: posterior spiracular plate. D. Detail of puparium: anterior spiracular processes. 272. A 13

0-5

D 273.

FIGURE 25.

L.PULLULA

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes. A

05 275.

PIGURE 25.

L.PULIXIA, Contd.

D. Detail of puparium: cephalopharyngeal skeleton of third instar larva.

B. Egg: dorso-lateral view. D 2.76.

0-1 277.

FIGURE 27.

L.CLINIVENTRIS

A. Third instar larva. B. Detail of third instar larva: anterior spiracular process. C. Detail of third instar larva: posterior spiracular process. D. Puparium (detail): anterior spiracular processes.

p\ 278.

C OS

0•I

0.1 279.

FIGURE 23.

L.CLAVIVENTRIS, Contd.

B. Egg: dorsal view. F. Egg: dorso-lateral view. 2s0.

LL-

Lil 281.

FIGURE 29.

L.CLAVIVENTRIS, Contd.

G. First instar larva: ventro-lateral view. 2.8z . G

0•I

283.

FIGUR 30.

L.CLUNIPES

A. Puparium (detail): anterior spiracular processes. 2- g

84011011°1161111114:11

0 • I 285.

PIGUlit 31.

L.PALMATA

A. Puidarium (detail): anterior spiracular processes.

236.

•

0 • I 287.

FIGUPE 32.

A. L.CLIJNIPES. dorso—lateral view. B. L.PALMATA. Egg: dorsal view.

289.

PIGURE 33.

L.BIPRONS

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes.

A 5 VI O.

0-5

0•I 291.

PIGUA3 34.

L.PARAPUSIO

A. Pupariuxn: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes. 2.9 z •

0.5

C 293.

PIGUaE 35.

1.PARAPUSIO, Contd.

E. Third instar larva. F. Detail of third instar larva: anterior end with cephalopharyngeal skeleton and anterior spiracular process. G. Detail of third instar larva: posterior spiracular process.

2.94.

E F

295.

IGURI3 36.

LoPSEUDONIVALIS

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of pupariumt anterior spiracular processes. A B 2-16.

0.5

0.1 297.

PIGURO 37.

L.LUTEILABRIS

A. Puparium: ventral view. B. Puparium: dorsal view. C. Detail of puparium: anterior spiracular processes. 298- A

o•5

o•i 299.

71GURE 38.

A. L.LUTEILABRIS. Egg: dorso-lateral view. B. L.PARAPUSIO. Egg: left lateral view.

301.

PIGURTI 39.

L.SFIKIPENNIS

A. Puparium: ventral view. B. Puparium: dorsal view. C. Detail of puparium: anterior spiracular processes D. Detail of puparium: cephalopharyngeal skeleton of third instar larva.

A 3oz.

0•1 303.

VIGUR' 40.

L. kTiaqIMA.

A. Pupnrium: dorsal view and ventral view. B. Puparium: anterior spiracular processes. C. Detail of puparium: cephalopharyngeal skeleton of third instar larva.

A 30

0-5

C 305.

IG1)RJ 41.

JJ.ATERRIMA, Contd.

D. Eggs: with first instar larva. I - 0

0.,,t o % • 0

614:74* / '64.* /

4v •or

O. Kao .7/

4 t

cr 307.

FIGUILL' 42.

L.ATOMUS

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of kuparium: anterior spiracular processes. 308. B

0.5

0•I 309.

?IGURE 43.

L.LEUCOP_LUA

A. Puperium: dorsal view. B. Puparium: ventral view. C. Detail of piparium: anterior spiracular processes. A B 310.

0-5

0.1 311.

FIGURE 44.

L.COPRIEA

A. Egg: dorsal view. B. dorsal view. M

cvaiLNLASZJL__AruuLss2 313.

'FIGURE 45.

L.PSOJDOLUGUBRIS

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes. D. Cephalopharyn,geal skeleton of third instar larva. 34..

A 5

0. I

C D

0-S 315.

'IGTIliE 46.

L.HilITULA

A. Pupariumo dorsal view. B. Detail of Euparium: anterior spiracular processes. C. Detail of puparium: cepiialopharyngeal skeleton of third instar larva. A 316.

0.1 317.

FIGURE 47.

A. I.(SPECIE3 A) n. sp. Thorax: dorsal view. B. L.PMGICOhA. Thorax: dorsal view. A 318.

3 319.

FIGURE 48.

A. L.(SPECIES A) n. sp. Male genitalia: from the right side. B. L.VUNGICOLA. :Male genitalia: from the right side.

c: cercus sp: supportini-!; plate fp: forked plate a: aedeagus gf: genital forceps pg: posterior gonapophyses 32.0.

0 321.

FIGURE 49.

A. L.(SPFJCIES A) n.sp. Male genitalia: aedeagus alone, from the right side. B. L.FUNGICOLA. Male genitalia: aedeagus alone, from the right side.

(Lettering as in previous figures: p. paraphallus) 3 22-

0 I 323. fiaGURE 50.

A. L.(sywins A) n. sp. hale genitalia: dors1 (actual ventral) view. a. L.PUNGICOLA. T ale genitalia: dorsal (actual ventral) view.

(Lettering as in previous figure: t 9, tergite nine; as, anal split) A 324..

O. I B

PY 325.

FIGURE 51.

A. L.(SPEf:IFIS A) n. sp. Wing (x 75). B. L.FUNGICOLA. Wing (x 60). 32.4). 327.

1- 0I RE 52.

L.(SPECIES A) n. sp.

A. Puparium: dorsal view. B. Puparium: ventral view. C. Detail of puparium: anterior spiracular processes. D. Third instar larva. IP 0 I

A 329.

FIGURE 53.

MAP OF SILWOOD PARK, BE'RKSHIRE. Showing position of suction traps (trap A at 30ft., trap B at 4ft.), collecting areas, and associated habitats.

Key to Map. C: site of meteorological screen. D: arable land. E & H: rough grassland. P: garden refuse tip. G: mown grass. I & K: stream and marsh. J & 1J: woodland (J is site of rabbit burrows investigated). M: broom plantation, with rough grass ground coverage.

111

k r I r r / 1 r . / l 1 j 1 1 a e • I I I 1 •

I I ' ' 1 . • 5 - .. .5.5 ..„. _ ...... 1 , 1 I % 1 1 ,11 j • I % ' , , _ _ _ _ , ,„/ ,,, ,,,, • ' 1 , i , • / s / ' r ' • / • l e , , , _• I * I • , o _- - - _ / , , _,/ t ---r — • • ',/ , -_, , \ , - - _ I "- - 7 / , , - I / I * - - ' % % / • I * / •, • 1 , , • I • , • , • • I 2 ? 1 „ 1 / I I , % I EP' •- • c,, • '. ' , , c-_;)i-_? 5 . • .., , , 9'1 •• , •,, I I I I 5 . I 1 , ‘ 1 . ... - - -• I . / ,_, • „ • ”, di . ', ,cfl, -4 • . . -...,.• I • I t I I, / ••• I I. I 1.4...,' ,,. :i;?c:=..q: q. E c709. 9,:,!::, ,, 0-gc I , „ , ' • 4\ tit ' , I I %,_ • , I o • • ,46#w ie:g - -• , il ro: 1 ; C ',?j,-c ,/ ,op 6 : ,, B-,.- . o 9 0 tr , •, / ,99',99 \ a, / 2 , 6 ici ‘,.. _ _ _ ------.-, , O , , ,,' ..„,,c-s1o yo 0,, , % / ko•-/ -- f', ', , •r--.....,‘' / ,--. , F , ..... •,, C) 4.1 • ' : ' : ' : ,--.:.> $;) • . .- , G ''s, ‘,, 0 -, • - ,,,,

I _ / • ,, i ; ,' i' ,' - —N— 1 0 , I I I r a x 1 : . I J. I/

SCALE 1:2500 331.

IGTJRI' 5 4 .

VAIIit,,T I 011 IN T:17.0-2, _/._.7.1.E.R.A CT FLIES 1h 24-1-10-UR C.: AT CH THAOTIGHOUT THE YEAR

A. S . PUS I ILA B . L . 1110, .SS TA C. L CLITICaPai D. I. MIRY I N.c.aPN S 332..

FIGURE 54.

15 4W

0 A W I5 OM NI B X u 15 I— a < u 0 C 30 < ce w . > 4

0 D 4 5 6 7 8 9 10 MONTHS 333.

PI GURE 55 .

SLASONAL CFANGES IN TRYi..; PERCENTAGE OT THE TOTAL PliPARIA CP b)C Ofri2f.E- FIVE MOY2 ABtNDAIIT SPECID3 IN THE RABBIT 3URROW BAIT-TR_LPS.

A. L.CLAVIVENTRIS B. L.Ba),UARTI o • L.PAJ,NATA D. C.PITAAIA • L.-rf:AWICATA FIGURE 55. 30-w

0 A 30

0 B 30 Joi sok-Olk• cc

< o 11111111111111 C 30 111 1 o 0 D 30 IU

0 E 6/77i11811/11915Falopi IV! 12/1 1/2117513/4 /5 6/7,8/9110111/12111 1967 1968 1969 335.

FIGURE 56.

3EASONAL VJIATILi IN Tat IMAIION GP DEVELOPMENT: Th.S pnkanNTAGn OF ENBRGING I! BACH OF &EVEN WEEKLY PSRIODS APTER COLLECTIO'N UP THE "BAIT" PROh TYE RI-.,BIT 3URROWS.

A. L.CLi,VIVENTRIS B. L.BEuLTABRTI 336.

FIGURE 56. 1967 506- 0 A 6/7 70 am, 0 B6/7 90

0 A 7/8 90 ta

0 B 7/8 O 50 0 A B/9 60

13.2 8/9 30011 A 9/10 40 0 B 9/10 3 4 5 6 WEEKS 331.

FIGURE 56 coNT. 1968 60

0 A 4/5 50

0 A 6/7 50

0 •••• I B 6/7 70

O A 7/8 60 U) (Li 73 0 6111 1 , 1 B 7/8 LL. 60 _...2 ° O A 8/9 50 O) B 8/9 70 1 I I '

O A9/10 70

B 9/10 O M -' r t, i , r 3 4 5 6 7 WEEKS