Bull. nat. Hist. Mus. Lond. (Geol.)56(1): 43^5 Issued29June2000 Burmapsilocephala cockerelli, a new genus and species of Asiloidea (Diptera) from Burmese amber GAIMARI S.D. Smithsonian Institution, Washington, D.C. 20560 USA MOSTOVSKI M.B. ArthropodLabioratory, PaleontologicalInstitute, RussianAcademy ofSciences, Profsoyuznaya Str. 123, Moscow 117647, Russia SYNOPSIS. PsilocephalaelectrellaCockerellisfigured,andanotherasiloidfly,Burmapsilocephalacockerelligen.etsp.nov., isdescribedfromBurmeseamber.ThenewgenusishypothesizedtobeclosetotheextantgenusApsilocephala.Thephylogenetic positionofApsilocephalaisdiscussed. INTRODUCTION slightlylongeranddoesnotappeartobeasfleshyasinApsilocephala. Postpronotallobehasasingle,strongseta.Mesonotumcoveredwith hairs. One pair of strong scutellar setae present. The foretibial Psilocephala electrella was described by Cockerell (1920) from macrosetaehavetheformula5v,5pv,5av,5pd,5ad.Thehindtibiahas Burmese amber based on an inclusion with incomplete wings and fewerthan lOpdmacrosetae. body. Through the courtesy ofMrA.J. Ross (Natural History Mu- seum, London) and Prof. A.P. Rasnitsyn (Paleontological Institute, Remarks. Burmapsilocephala is taxonomically close to the ex- Moscow) the collection of flies in Burmese amber stored in the tant genus Apsilocephala Krober, 1914, with only minor Natural History Museum, including the holotype of this species morphological differences. In Apsilocephala the pedicel is about (In.20148)(Fig. 1),wasavailableforstudy.Itisdifficulttobecertain halfthelengthofthescapeorfirstflagellomere,whicharesubequal. thatthisspeciesbelongstothegenusPsilocephala,becausecharacter- Theantennalstylusis 1.0to 1.5 timeslongerthanantennalsegments istic features are not preserved. Another specimen (In.20167) (Fig. 1-3. The postpronotal lobe has long hairs but no macrosetae. Two 4)belongingtothesuperfamilyAsiloideawasdiscovered,withwing pairs ofscutellarsetae are usuallypresent, althoughonepaircanbe venation and leg structures resembling those of the holotype of strongerthan the other. The foretibia ofApsilocephala has only 2- Psilocephala electrella. However, itdiffersfromthelatterinhaving 3pdand0-lad,andhindtibiahasmorethan 1Opd.Burmapsilocephala a slender body and more robust thoracic bristles, except for the differsfromApsilocephalaandtherevids,inpossessingalongstylus dorsocentrals. On balance, itprovedto be arepresentative ofa new and vein R5 ends near the wing tip. Remarkable is the absence of genus describedhere. robust dorsocentrals inBurmapsilocephala. Burmapsilocephala cockerelli sp. nov. Figs 2-A SYSTEMATIC DESCRIPTIONS Name. The name is in the memory ofT.D.A. Cockerell. Material and locality. Holotype In.20167, from Burmese The following abbreviations are used: amber,HukawngValley,Myanmar(Burma);probablyUpperCreta- Forthoracicmacrosetae:ppn=postpronotal,npl=notopleural,sa ceous (see Zherikhin and Ross, this volume). = supraalar,pa = postalar. For the positions of setal rows in tibiae: v = ventral, pv = Description. Female, the tip ofabdomen not discernible. Body posteroventral,av=anteroventral,d=dorsal,pd=posterodorsal,ad and legs slender. = anterodorsal. Head: Fronsnarrow,bare.Ocellartrianglenearlyflattened. Scape (1), pedicel (2), and firstflagellomere (3) subequal inlength. Scape and pedicel with short hairs apically. First flagellomere slightly OrderDIPTERA tapered to apex. Stylus apical, 2.5 times longer than segments 1-3 SuperfamilyASILOIDEA combined. FamilyAPSILOCEPHALIDAE Thorax (Fig. 2): Postpronotal lobe relatively large. Mesonotum GenusBURMAPSILOCEPHALA nov. highly arched, covered with short hairs. Postalartubercles distinct. Macrosetal pattern: Ippn, 2npl, \sa, \pa. Scutellum small, trapezi- Name. The name is derived from Burma, and the genus name form; with 1 pair strong macrosetae; covered with long hairs. Apsilocephala. Pteropleuron bare. Metathorax relatively large. Halter pale with darkerknob. Fascicle oflong delicate hairs anteriorto halter. Type species. Burmapsilocephala cockerelli nov. Wing (Fig. 3) with cell m3 closed and stalked; costal vein termi- Diagnosis. Scape, pedicel, and first flagellomere subequal in nates at wing tip. length.Antennalstylus2.5 timeslongerthanantennalsegments 1-3 Legs: Coxae with long hairs. Hind femur without macrosetae. combined, and slightly thinner than in Apsilocephala. Proboscis Foretibia with apical ringlet of five macrosetae, and rows of ©TheNaturalHistoryMuseum,2000 44 S.D. GAIMARI AND M.B. MOSTOVSKI Fig.4 Burmapsilocephalacockerelligen. etsp. nov.,holotypeIn.20167, Burmeseamber. Length5.3mm. Fig. 1 PsilocephalaelectrellaCockerell,holotypeIn.20148, Burmese amber.Widthofwing 1.5mm Tergite 2 longer than others; tergite 7 slightly shorter than others. Tergites dark with pale, narrow band along lateral and posterior macrosetaewithformula5v,5ad,5pd,5pv,5av.Midtibiawithapical margins.Tergites 1-5coveredsparselywithshorthairs;6-8covered ringletof4-5 macrosetae, androws ofmacrosetaewithformula3d, with short hairs. Tergite 9 smaller and slender than the others, with 4ad, 2p, 3pv, 2pd. Hindtibia with asymmetrical, apical ringlet of long and short seta-like hairs. macrosetae, and rows ofstrong and weak macrosetae with formula 3ad, 1 (?8)pd, \pv (in distal third), 6av. Metatarsus with rows of Measurements. Bodylength(withoutantennae)=5.3mm,wing strong hairs ventrally (at least in basal half), and with lateral setae, length = 2.7mm, wing width = 1.2mm. and with 4 (?5) strong apical setae. Tarsal segments 2-5 haired and DISCUSSION. Apsilocephalawasoriginallydescribedasamember with apical setae. Empodium bristle-like. Pulvilli and tarsal claws of the Therevidae (Krober, 1914), but this certainly represents an small. enigmatic genus. Apsilocephala was considered separate from Abdomen(Fig.4):Tergite 1 threetimesshorterthantergite2;with Therevidae byIrwin (1976) andIrwinandLyneborg (1981), butthe lateral fascicles of long hairs. Tergites 3-6 subequal in length. positionofthegenuswasnotconsideredfurther.Apsilocephalawas givenfamilystatus,andincludedthegeneraClesthentiaWhite, 1914 and ClesthentiellaNagatomi, Saigusa, NagatomietLyneborg, 1991 (Nagatomietal, 1991a).However,themonophylyofthegroup,orat least its ranking at family-level, was questioned due to absence of definitive synapomorphies (Sinclair etal, 1994). The phylogenetic comments herein do not address the monophyly or internal classi- fication ofthe familyApsilocephalidae, butonly its position within the Diptera. Nagatomi et al (1991a, c) hypothesized a close affinity of Apsilocephalidae with the Middle to Late Jurassic family Rhagionempididae based on superficial similarities, but noted that the most important characteristics (e.g. male and female genitalia, condition of empodium) are not known in the rhagionempidids. Nevertheless, Nagatomi and Yang (1998) did synonymize Apsilocephalidae under fossil Rhagionempididae. It seems to be precociousnow.Further,Nagatomietal(1991a, b, c)andNagatomi (1992, 1996) hypothesized a sister-group relationship with Empidoidea or with Eremoneura, based again on the presence of surstyli in the male genitalia. Griffiths (1994, 1996), Sinclair et al (1994), Cummingetal(1995), andZatwarnicki (1996)rejectedthis hypothesis based on the observation that the 'surstyli' of Apsilocephalidae were erroneously considered homologous to the structuresofEmpidoideaandEremoneura. Sinclairetal(1994) and Figs2,3 Burmapsilocephalacockerelligen. etsp. nov.,holotype Cumming etal (1995) retained the genusApsilocephala within the In.20167,Burmeseamber. 2,headandthorax; 3,wingvenation; scale concept ofTherevidae, but as incertae sedis (without further com- bar 1mm. menton Clesthentia or Clesthentiella).Additional considerationby NEW ASILOIDEA FROM BURMESE AMBER 45 Yeates (1994) also maintained this position ofApsilocephala very ACKNOWLEDGEMENTS. TheauthorswouldliketothankMrAJ.Rossfor near to Therevidae, and current morphological (M.E. Irwin, pers. access to the collectionofDipterain BurmeseamberattheNatural History comm.)andmolecular(L.L.YangandB.M.Wiegmann,pers.coram.) Museum, London, and Prof. A.R Rasnitsyn forencouraging this work, Drs studies also suggest that Apsilocephala is very near or possibly N.L.Evenhuis,M.E. Irwin,andanonymousrefereeforreviewingthemanu- within Therevidae. 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