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BR. J. ENT. NAT. HIST.,4: 1991 123 INVREIA SUBARMATA FORESTER (HYMENOPTERA: CHALCIDIDAE) AT DUNGENESS, KENT R. K. A. Morris and M. S. Parsons TheNature Conservancy Council, NorthminsterHouse, Peterborough PE1 1UA*. Boucek(1972)reportedthecaptureoffourspecimensofInvreiasubarmatawhich wereswept fromshortgrassatDungenessin 1971. Thecaptureofthisspeciesin 1988 and again in 1989, in pitfall and water traps during a Nature Conservancy Council surveyofDungeness, is therefore not entirely surprising. The samplegenerated was substantial however, and provides an indication of the ecology of this species at Dungeness. Priorto 1988, publishedrecordsof/. subarmatawerelimitedtoasingle 19thcenturyrecordfromPortland(misidentifiedas/. subaeneainFerriere&Kerrich 1958) and the four individuals taken in 1971 at Dungeness. In 1988, the NCC undertook a survey ofthe invertebrate fauna ofDungeness as part ofwork commissioned by the then Central Electricity Generating Board (now Nuclear Electric). Twenty trapping stations were established in 1988 and were maintainedbetweenMayandOctober. DataonthetrappingstationsisgiveninMorris &Parsons(1991b). In 1989, thestudywasextendedtocoverthewholeoftheshingle system at Dungeness and others elsewhere in south-east England. As a result, 37 trapping stations were established at Dungeness with a further 10 at Rye Harbour, EastSussex. Eachtrappingstationcomprisedalinearrunoffivepitfalltraps(plastic vending cups) spaced at approximately two metre intervals, and two white water pitfall traps water traps Trapping Period 23.5-6.6-1989 1 2 06-20.6 -1989 3 20.6-57-1989 4 29.8-12.9-1989 5 12-279-1989 Break trapinping Fig. 1. Numbers ofindividuals of Invreiasubarmata taken in pitfall and water traps during 1989. 2 3 Trapping Period *Presentaddress:TheJointNatureConservationCommittee,MonkstoneHouse,CityRoad,Peterborough PE1 1UA. 124 BR. J. ENT.NAT. HIST.,4: 1991 traps(whiteplasticbowls20cmindiameterand9cmdeep). Boththepitfallandwater traps were partially filled with a mixture of 10% ethylene glycol in water and were emptiedevery2weeksduringtwotrappingperiods;23Mayto5 Julyand29Augustto 27 September. ThelocationsofthesetrapsaredescribedinMorris&Parsons(1991a). During the survey in 1988, parasitic Hymenoptera were not a target group and only a limited sample of material was retained. As a result, data for this period is onlyavailablefromtrappinginAugustandSeptember. In 1989, aninterestinasmall group ofparasitic Hymenoptera led to recording of Chalcididae. For the purposes of this article, the comments are therefore confined to the results of work in 1989 whenitwaspossibletoextractallrelevantmaterial. In 1989, atotalof380individuals of/, subarmatawererecorded. Figure 1 showsthenumberscapturedineachtrapping period and from the available data, the peak frequency of/. subarmata appears to be August but, as there was a gap between trapping periods, this is not certain. Thereis adistinct succession ofvegetation types at Dungeness which is described by Ferry and Barlow (in Ferry&Walters 1985). Further studies and a classification ofshinglevegetationaredescribedbyFerryetal. (1990)and, asaresultofthiswork, the vegetation is mapped by Fuller (1989). The trapping stations were arranged so that they remained within a distinct vegetation type and therefore, it is possible to compare the results ofpitfall and water trapping against vegetation type (see Ferry et al., 1990, page 94). Comparing the average number of individuals per trap run Keyto VegetationTypes Crambe 1 2 Arrhenatherum B3 3 Acid heath A1 4 Acid heath A2 5 Acid heath A2S 6 Acid heath A2 7 Acid heath A3f 8 Mesotrophic B1 9 Wetland B2 Wetland with Salix B2S Bareshingle Alluvial soil Sand == Vegetation type Fig. 2. Average numbers ofInvreiasubarmata related to trapping effort and habitat type. BR. J. ENT. NAT. HIST.,4: 1991 126 BR. J.ENT. NAT. HIST.,4: 1991 attention to the more recent record of /. subarmata. We also thank Dr R. S. Key for help and advice during the preparation of this note. References Boucek, Z. 1952. The first revision of the European species of the family Chalcididae (Hymenoptera). Sborn. Nas. Mus. Praze 27: (Suppl. 1): 1-108+17 pi. Boucek, Z. 1972.OnsomeEuropeanChalcididae(Hymenoptera), withadescriptionofanew Euchalis Dufour. Ent. Gaz. 23: 237-242. Ferry, B. W. & Walters, S. 1985. Dungeness, ecology and conservation. Focus on Nature Conservation 12. The Nature Conservancy Council, Peterborough PE1 1UA. Ferry,B.W.,Lodge,N.&Walters,S. 1990.Dungeness:avegetationsurveyofashinglebeach. Research and Survey in Nature Conservation 26. The Nature Conservancy Council, Peterborough PE1 1UA. Fuller, R. 1989.Dungenessvegetationsurvey—mapping. TheInstituteofTerrestrialEcology, Monks Wood. Report to the NCC. Ferriere, C. & Kerrich, G. J. 1958. Hymenoptera: Chalcidoidea. HandbkIdent. Br. Insects 8(3b). Royal Entomological Society, London. Morris,R.K.A.&Parsons,M.S. 1991a.A Surveyofinvertebratecommunitiesontheshingle ofDungeness, Rye Harbour and Orford Ness. Contract Survey 120 (in prep.). Joint Conservation Committee, Peterborough PE1 1UA. Morris, R. K. A. & Parsons, M. S. 1991b. An invertebratesurvey ofaproposedDungeness 'Cstationstudyarea.ContractSurvey 133.TheNatureConservancyCouncil,Peterborough PE1 1UA. BENHS FIELD MEETINGS Shortheath and Slab Commons, East Hampshire, 24 June 1990 Leader: S.R. Miles. Sixmembersattendedthisdaytimemeeting. Fortunatelyearly sunshinehadbroughtoutvariousinsects, howeveruntypicallyfor 1990therainclouds were gathering. The party admired the large amounts of cranberry (Vaccinium oxycoccus L.) in the bog at Shortheath Common, some still in flower. Some large horseflies Tabanus autumnalis L. were seen at rest on dead birch tree boles, as by this time it had become overcast. Andrew Halstead took a single specimen of the local flyAcrocera orbicula F. swept from long grass adjacent to the bog. As larvae theseareobligateparasitesofspiders. Thehoverfly Trichopsomyiaflavitarsis(Meig.) whichislocalinsouthernEnglandduetoitsrequirement forwetheathlandwasfairly frequent withintheconfines ofthe bog. Andrew was also fortunate to take a single specimenofthehoverflyHeringiaheringi(Zett.) and anexampleofthelocal sawfly Aneugmenus temporalis Thorn. Peter Chandler found two local fly species, the scathophagid, Pogonota barbata (Zett.), which he informs me also occurs on the nearby Surreybogs and theMycetophilid, RymosiaarmataLac, whichis a fen and lakeside inhabitant. AfterlunchthepartywalkedtothenearbysiteofSlabCommon, whichisanarmy tracked-vehicletraining and recovery area. This is what I term degraded heathland, however because ofthe army use it retains considerable open bare sandy areas. At the margins of these many small flowering plants occur, including various small Compositaewhichwouldprobablybeout-competed bymore rankgrowth ifit were not for the continued erosion. Some local solitary bees occur here, however as the weather was most unfavourable, by now windy as well as verycloudy, few aculeata were seen. Frances Murphytook aninteresting linyphiid spider, Erigonepromiscua (O.P.-C.)andPeterChandlerwasalsopleasedtocapturetwofliesofdampwoodland,