©EntomologicaFennica. 16 September2005 Scuttle flies (Diptera: Phoridae) of saline habitats of the Gulf of Gdansk, Poland EwaDurska, ElibietaKaczorowska&R.HenryL.Disney Durska, E., Kaczorowska, E. & Disney, R. H. L. 2005: Scuttle flies (Diptera: Phoridae)ofsalinehabitatsoftheGulfofGdansk,Poland.—Entomol. Fennica 16: 159—164. Resultsofasurveyofthescuttleflies(Diptera:Phoridae)ofsalinehabitatsofthe GulfofGdanskarereported. Withinthreestudyseasons(1999—2001), atten10- calities representing coastal brackish and maritime habitats, 39 phorid species were collected. Among these, 36 were new to these areas, andXenotriplzleba dentistylata Buck was the first record for Poland. The dominance structure, phenologyandabundanceofphorids ofsalinehabitats aredescribed. E.Durska,MuseumandInstituteofZoology,PAS, Wilcza64, 00—679Warszawa, Poland;E—mail.‘ [email protected] E. Kaczorowska, Department ofInvertebrate Zoology, University ofGdansk, Pilsudskiego46,81—378Gdynia,Poland;E—mail.‘[email protected] R. H. L. Disney, UniversityMuseum ofZoology, Cambridge CB2 3EJ, United Kingdom;E—mail.‘ [email protected] Received23 October2002, accepted9November2004 1. Introduction the tides and rainfall. Its eggs, being in a con- stantlyhighhumidity, areatypicallythin-walled, Scuttleflies(Phoridae)areoneofthemostabun- seemingly because they are not exposed to the dantfamiliesofDipteraand“theprimecandidate risk of desiccation. Records of scuttle flies in forbeingthemostbiologicallydiverse familyof maritime habitats are otherwise sparse, apart insectsontheplanet”(Disney 1990, 1994). One- from scatteredrecords andreports, such as pho- quarteroftheca.3,000speciesdescribedoccurin rids and other Diptera trapped in the oil oozing thePalaearcticRegion. fromadeadwhale(Cobert&Disney 1998).Mar- The seashore is generally not regarded as a itimehabitats havenotbeensystematically sam- suitable habitat for Phoridae, but the larvae of pledforPhoridae. some New World species of Megaselia are InPoland,littleisknownaboutscuttlefliesof knowntobeintertidalandthus abletocopewith salinehabitats. Szadziewski(1983),investigating fluctuationsinsalinity(Saunders 1928, Cheng& Diptera ofthese areas, found only eight phorid Hogue 1974). Disney (2002) reported that the species. All ofthesewere haloxenes i.e. species EuropeanMegaseliayatesiliveswithinthevoids thatoccuranddevelopnumerouslymoreoftenin ofthe first shingle ridge above high watermark specificnon-salinethaninsalinehabitats. Inthis andthat its larvae are likely to be subjectedto a paper,wereportonthephoridsofthebeachesand range ofsalinities following the fluctuations of coastalbrackishareas oftheGulfofGdansk. 160 Durska etal. ' ENTOMOL. FENNICAVol. 16 2. Material and methods 2001, 1—2 times aweek. Flieswere collectedby sweeping (using an entomologicalnet) overwa- 2.1. Study area ter’s surface, algae washed ashore, soils, plants overgrowing dunes and cliffs, and in halophyte Materialwascollectedontenareas, representing communitiesgrowingnearthesaline-waterreser- twotypesofhabitatborderingtheBalticSea—the voirs. All scuttleflieswerepreservedin75% al- coastal brackish and marine habitats. The first cohol. Megaselta females were not identifiedto areawas at the Bay ofPuck and Gdansk—Gorki species. Wschodnie, and the second one was formedby Todescribethedominancestructureofcommu- theeightbeachesadjacenttotheGulfofGdansk. nities, a dominance index (D) was used (Durska The brackish area, viz. Gdansk—Gorki 2001): Wschodnie (the coastal type), is situated at the mouthoftheWisla Smialariver. The salinearea D=n/N* 100% (1) beside the river comprises bulrushes, brackish marshes and brackish meadows. The latter are wheren=theabundanceofagivenspecies,andN= overgrown by halophytes such as Aster tripo— theaccumulatedabundanceofallphoridspecies. lium, Triglochin maritimum, Glawc maritima, Thedominanceindex(D)wasusedto classify andArtrl'plex hastatum var. salinarium. On the the species into fourclasses: (1) eudominant(over stony dam, Aster tripolium, Atrl'plex hastatum, 15.0%), (2) dominant (flom 5.1% to 15.0%), (3) Spergularia salina, Elymus arenarius, Solanum subdominant (flom 1.1% to 5.0%) and (4) acces- dulcamara and Sonchus arvensts can be found. soryspecies(upto 1.0%). Stonesintheriverbottomandfloodedpartsofthe dam—wherematerialwasalsocollected—areco- vered with algae Enteromopha sp. and Clado— 3.Results phora sp. ThefliesoftheBayofPuckwerecaughtover The material contained 230 phorid imagines. The coastal waters, and in brackish marshes and phorid fauna of the saline habitats sampled meadowsalongthewaterside. Thebaybanksare provedtobericher(39 speciesbelongto 11 gen- coveredwithPhragmttescommunts,whereas on era)thanexpected, inviewofthelimitedcollect- the meadows occur Trtglochtn martttmum, ingbymeansofnettingonly. Themostabundant Atrl'plexhastatum var. salinum,Astertripolium, genusMegaselta was representedby 21 species Glaux maritima and Spergularia salina (Szad— (onlymales,ca.60%ofthetotalcatch)(Table1). ziewski 1983). The fFlieswerecollectedin supralittoral and epilittoralzonesoftheeightbeachessituatednear 3.1.Dominancestructure Gdynia — Wzgorze Swietego Maksymiliana (Gdynia—Wzgorze), Gdynia — Orlowo (UTM: The cumulative abundance of the three eu- CF44), Sopot, Gdansk — Jelitkowo, Gdansk — dominant (M. subnudipennis, M. ignobilis, M. Brzeino(UTM: CF43), Gdansk—GorkiWscho- pultcartacomplex)andonedominantspecies(M dnie (UTM: CF52), Wladyslawowo (UTM: brevtcostalts) exceeded 60% ofthe total catch. CF37)andUstka(UTM:XA25). Theseareasare Thesubdominantswererepresentedbyninespe- flatandsandy,andonlythelocalitynearGdynia— cies (Fig. 1). Among the species ofthe lowest Orlowo, adjacentto thecliffs, is alittle stony. abundance, one male of Xenotrt'phleba denti— stylata(Buck, 1997)wascollectedin27thofMay, onthebeachnearGdynia—Brzezno. Itisthefirst 2.2.Phoridsampling, and statisticalmethods recordforPoland. PhoridswerecollectedfromthebeginingofMay totheendofSeptemberin 1999andfromthebe- ginning of April to mid October in 2000 and ENTOMOL. FENNICAVol. 16 ° Scuttleflieson the GulfofGdansk 161 Table 1. Speciescomposition, abundanceand phenologyofPhoridaeinsalinehabitatsoftheGulfofGdansk (1999—2001). *=speciesnewtothe Polishfauna Specimens/month Species Larvalfeeding IV V VI VII VIII IX X total % 1 Borophagafemorata (Meigen) unknown — — — — — 1 — 1 0.43 2 Borophagasubsultans(Linne) unknown — — — 6 — — — 6 2.61 3 Conicera dauci(Meigen) saprophagous — — — 2 — 1 — 3 1.30 4 ConicerafloricolaSchmitz saprophagous — — — 1 — — — 1 0.43 5 Conicerasimilis(Haliday) necrophagous — — 1 — — — — 1 0.43 6 ConiceraschnittmanniSchmitz saprophagous — — — — 1 — — 1 0.43 7 Dorhniphora cornuta polyphagous — — — 1 — — 1 0.43 (Bigot in De La Sagra) 8 Diplonevranitidula (Meigen) zoophagous — — — — — 1 — 1 0.43 9 Gymnoptera vitripennis(Meigen) zoophagous — — — 1 — — — 1 0.43 10 Megaselia aculeata (Schmitz) ?saprophagous — — 1 — — — — 1 0.43 11 Megaselia affinis(Wood) unknown — — — 1 — — — 1 0.43 12 Megaselia brevicostalis(Wood) saprophagous 2 — 1 7 — — — 10 4.35 13 Megaselia campestris(Wood) unknown — — — 2 — — — 2 0.87 14 Megaselia ciliata (Zetterstedt) zoophagous — — — 1 — — — 1 0.43 15 Megaselia diverse (Wood) ?saprophagous — — — — — 1 — 1 0.43 16 Megaselia emarginata (Wood) unknown — — — 1 — — — 1 0.43 17 Megaselia errata (Wood) saprophagous — — 1 — — — — 1 0.43 18 Megaseliagiraudii(Egger) polyphagous — 3 — 2 — — — 5 2.17 19 Megaselia hirticrus(Schmitz) ?saprophagous — — 1 — — — — 1 0.43 20 Megaselia hortensis(Wood) ?saprophagous — — — 1 — — — 1 0.43 21 Megaselia humeralis(Zetterstedt) unknown — — — — — 1 — 1 0.43 22 Megaselia ignobilis (Schmitz) unknown — 7 11 1 6 — — 25 10.87 23 Megaselia involuta (Wood) unknown — — 2 — — — — 2 0.87 24 Megaselia manicata (Wood) ?saprophagous — 1 — — 1 — — 2 0.87 25 Megaseliapleura/is(Wood) saprophagous — — — — — 1 — 1 0.43 26 Megaseliapulicaria complex polyphagous 4 3 — 9 2 2 — 20 8.70 (Fallen) 27 Megaseliapumila (Meigen) unknown — — 1 — 1 — — 2 0.87 28 Megaselia ruflcornis(Meigen) necrophagous — — 1 1 — — — 2 0.87 29 Megaselia subnudipennis(Schmitz) necrophagous — 9 25 9 10 — — 53 23.04 30 Megaselia verralli(Wood) unknown — — — 2 — — — 2 0.87 31 Megaseliasp. (females) X 3 8 16 19 17 7 — 70 30.43 32 Phoraan‘ifronsSchmitz unknown — — — 1 — — — 1 0.43 33 Phoraatra (Meigen) saprophagous — — — 1 — — — 1 0.43 34 PhoraedentataSchmitz unknown — — — 1 — — — 1 0.43 35 PhoraholosericeaSchmitz zoophagous — — 1 — — — — 1 0.43 36 Pseudacteonformicarum(Verrall) zoophagous — — — 1 — — — 1 0.43 37 Spiniphorabergenstamni(Mik) necrophagous — — 1 — — — — 1 0.43 38 Spiniphora dorsalis(Becker) ?saprophagous — — — 1 — — — 1 0.43 39 Triphleba dudai(Schmitz) saprophagous — — — 1 — — — 1 0.43 *40 Xenotriphleba dentistylata Buck ?saprophagous — 1 — — — — — 1 0.43 Total 9 32 63 72 39 15 0 230 100.00 3.2.Phenology 2). The first individuals of Megasell'a sub— nudipennis(23% ofthetotalcatch) andM. igno— During the study, the highestnumber ofspecies bz'lz's (10.9%) were recorded in May. The abun- andspecimenswereobservedinJulyandalso in dancepeaksofthesetwospeciesoccuredinJune. June,andthelowestnumberinAprilandSeptem- M. pulicaria — complex (8.7%) and M. brevi— ber. In October no phorids were collected (Fig. costall's (4.4%) had their abundance peaks in 1621 Durskaata]. 0 ENTOMOL. FENNICAVol. 16 40 — 35 fl 1 UI-Megaseliasubnudzpennis w m.2-Megaseliaignobilis 30 - D3-Megaseliapolicaria \a2“ 25 - UU45--MBoergoapslzeaiigaabsruebvsicuoltsatnaslis g 20 M U6—-Megaseliagiraudii g “in U7~Coniceradauci m 15 3 U8_,Megasclr’acampestris 10 -» UU910..~MMeigaasseelialiainmvoalnuitcaata F.ig 1IThedomi.nance 5 ~ 8 9 m 11 12 n11*Megasemmmfla structureofthephond CGanunitieSinsaline 0 l i 5 l 1‘ U12-Mcgaseliamficornis species(males.abundance21%) D13 "Megaselia””th habitatSOftheGun:(3f U14-others GdafiSk. 60 W W 50 “m 40 "m 30 .. {W.....«-. *M. ‘t N‘ 20 .. Fig.2. Seasonal . 1 changesinthenumber to -.. ofphenolspecies(3) 0 t i l l ‘i? ...,l...‘“e aanbdunrdealanticvee(pnh)oinridsaline VI VII VIII IX X habitatsoftheGulfof months GdafiSk. July. Their first individuals were collected in 64%). but in Gdynia—WzgorzeM ignobilis (ca. April. 21%) dominated. ln Gdansk—Germ Wschodnie The phenology ofthese four most common nophoridswerecollected. Megaselia species were characterised by one Thesaprophagousandnecrophagousphorids abundancepeakduringthesummer(Junemluly). (over50%)werethemostabundantgroupofspe— cieswithknownlarvaldiets.(Fig.4).Theirabun— dancepeaksfellintheSimmer(JunemJuly)when 3.3. Species richness and abundance, most organic matter (mostly algae and fishes) andtrophicgroups waswashedashore(Table 1). Four Megaselia species M diver/ca, M The highest number ofphorid species were re— lair/“times. M. pleuralz’s and M. pumila were re— corded on beaches situated near Gdyniam cordedonthemeadows andswamps ofthe Gulf Wagorze(over56%ofthespeciesrecorded) and ofPuck (salinity ca 7.4%). These species were Wladyslawowo (over35% ofspecies) (Fig. 3). notobservedintheotherinvestigatedhabitats. Thehighestabundanceofscuttleflieswasre— cordedforthebeachesinGdynia—Wzgorze(over 42% of the total numbers of specimens) and 4. Iiscussion GdanskmBrzeézno (over29%) (Fig. 3). The latter locality is a typical sandy beach, with dunes. In Szadziewski (1983) during his investigation. of Gdafisk—Brzefino, the most numerous species saline flies in differenthabitats ofPoland found wasnecrophagousMegaseliasubnudipemis(ca. infrequentphoridspecies:Acm’gmatiasZubbockii ENTOMOL. FENNlCAVol. lo ° Scuttleflieson the Gil/(ZfOdeaI/lSk 60 50 -_ 40 —- ’9‘.‘ a? m 30 ~~ Q“ 20 ‘k Fi.g. 3. Compari.sonof to - . 10 thenumberofspecies 0 m (S)andabundance(n) 60 will“ at, $0 “12% (I $0 $0 ofPhoridaeinsaline {a 99“ m“? 04g? 451? s9 09C) $9 habitatsoftheGulfof ‘2’ \9 “9 ,s Gdansk. «sf 40 ~- 9.. 30 ~ W . 0‘ x as: ‘. . ‘. ‘ :20 ~~ “.. W. N‘ Fi.g.4. Compari.sonof 10 -~ r thenumberofspecies (8)andabundance(n) 9 ofPhoridaeofdifferent 0gp 0‘)?» (,5; 00s a" 095:.» trophicgroupsinsaline st? ’29 a» s9 s9 s9 st 9*“ «$1 é“ <5“ as habi.tatsoftheGulfof $9 (£9 $9 at) $09 Gdansk. " ”if” “‘4‘ (Verrall), Megaselia brevicosralis (Wood), M foundthetrulyhalophilicspecies.Allofthespe- minute (Aldrich), M ptrmila (Meigen), M stig~ cies found. in saline areas are known to occupy matica (Schmitz), M. unguicularis (Wood), otherhabitats, andthe most ofthem are consid- Pseudacteonfor/’mz’camm (Verrall) andP. [and-- ered as members ofthe soil—borne insect fauna heater” Schmitz. Szadziewski (1983) caught no (Buck 1994-, Weber & Schiegg 2001). Saprou phoridsin.marinehabitats. However, inbrackish phagous andnecrophagous species dominate es" areaofthecoastaltype,Szadziewskicollectedsix peciallyopensitessuchasopenwoodlands(pine of the above-mentioned species: in Gdansk—— plantations) and. agricultural habitats (Prescher Gorki Wschodnie, he collected M pumz’ia, M 1992, Disney 1994, Buck 1997, Durska 2001, stigmatica, M. unguicularis, P.formicarzrm and 2002) P. inndbecki, and.M brevicostalisonthelocality inthe costal brackish.habitats nearPuck, we adjacent to the GulfofPuck. in our study, only caughtonly1lphorid.individuals(M.diverse,M. three of these species were found, viz. M hirticms,Mpleuralis,Mpumflaand.Megaselia brevicosralis andP.formicartrm onthe beaches, spp. females). Ofthese,M. diverse andM.pleu— butMpumila was foundnearthe GulfofPuck. ralishavepreviouslybeenrecordedbyCorbet& Thelack.ofphoridsinGdan_skaork_iWschodnie Disney (1998) among Dipteratrapped inthe oil wasrelatedtothefewsamplescaughtonthis 1.0-- oozingfromadeadwhale. cality. The scuttle flies with saprophagous and/or Neither the authors nor Szadziewski (1983) necrophagous larvae, reported from saline habi— 164 Durska etal. ' ENTOMOL. FENNICAVol. 16 tats, belong to the most abundanttrophic group. Buck, M. 1997: A new genus and species ofPhoridae However,phoridfaunaismorenumerousinother (Diptera)fromCentralEuropewithremarkablyprimi- maritime habitats. The beaches adjacent to the tivemaleganitalia.7Ent. Scand.28: 3517359. Cheng,L.&Hogue,C.L. 1974:Newdistributionandhabi— Gulf of Gdansk are rather polluted and have tatrecordsofbitingmidgesandmangrovefliesfrom abundant organic matter, such as decaying ani- thecoastsofsouthernBajaCalifornia, Mexico (Dip— malsandwashed-ashorealgae,thatattractsapro- tera: Ceratopogonidae, Culicidae, Chironomidae and phagous flies. Phoridae).7Ent.News85: 2117218. In another study, among 51 families ofDip- Corbet, S.A.&Disney,R.H.L. 1998:Dipteratrappedin teraofsalinehabitats ofthe GulfofGdansk, the theoiloozingfromadeadwhale. 7Entomologist’s Mon.Mag. 134: 344. abundance ofthe scuttle flies madeup 0.75% of Disney,R.H.L. 1990:Somemythsandtherealityofscuttle thetotalcatch(14 samplingpositions; E. Kaczo- flybiology.7Antenna 14: 64767. rowska, unpubl. data). The most abundant taxa Disney, R. H. L. 1994: Scuttle flies: The Phoridae. 7 were Chironomidae (ca. 28%), Ephydridae (ca. Chapman&Hall,London. 467pp. 20%) and Chloropidae (ca. 14%). Phorids, with Disney,R. H.L.2002:Anewspeciesofmaritimescuttle the majority being saprophagous and necro- fly (Dipt., Phoridae) from East Sussex, England. 7 phagous species, peakedinJuly, whentheyrep- Entomologist’sMon.Mag. 138: 19722. Durska, E. 2001: Secondary succession of scuttle fly resentedalmost30% oftheDiptera. (Diptera: Phoridae) communitiesinmoistpineforest inBialowieZaForest.7Fragm.Faun.44: 817130 Acknowledgements. We thank DrMatthias Buck forhis Durska, E. 2002: The phenology ofdominant scuttle-fly commentsonearlierversionofthemanuscript. (Diptera: Phoridae)speciesintheBialowiezaForest. 7Entomol. Fennica13: 123—127. References Prescher, S. 1992: Gkologie und Biologie der Diptera, insbesondere der Brachycera, eines Klarschlamm— Buck, M. 1994: Sphaeroceridae and Phoridae (Diptera) gediingtenAckerbodens.7PhD. thesis,Universitat collectedby emergence traps fromvarious terrestial Carolo-WilhelminazuBraunschweig. habitatsinsouthernGermany.7StudiaDipterologica Saunders, E. 1928: Some marine insects ofthe Pacific 1: 937106. coastofCanada.7Ann.Ent.Soc.Am.21:5217545. Buck, M. 1997: Untersuchungen zur Gkologischen Szadziewski,R. 1983:Flies(Diptera)ofthesalinehabitats Einnischung SaprophagerDipterenunterbesonderer ofPoland.7P01. PismoEntomol. 53: 31776. Beriicksichtigung der Phoridae und Sphaeroceridae Weber, G. & Schiegg, K. 2001: Scuttle flies (Diptera: (Brachycera/Cyclorrhapha). 7 PhD. thesis, Uni- Phiridae) from the forest reserve Sihlwald ZH. 7 versitatUlm. StudiaDipterologica8:2717276.