View source for Trichosiopsis dimera

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{{Treatment start
 | Ordo = Diptera
 | Familia = Sciaridae
 | Genus = Trichosiopsis
 | Specific name = dimera
 | Infraspecific name = 
 | Taxon rank = species 
 | Taxon authority = Tuomikoski, 1960
 | Taxon status = 
 | Nomenclature citation = {{Nomenclature citation |''Trichosia (Leptosciarella) dimera'' {{aut|Tuomikoski, 1960}}<ref name="SC043">{{aut|Tuomikoski, R.}} 1960: Zur Kenntnis der Sciariden (Dipt.) Finnlands. ''Annales Zoologici Societatis Zoologicae Botanicae Fennicae “Vanamo”'', '''21''', 1–164.</ref>: 23-24; fig. 4a, 5a, 5g}}
{{Nomenclature citation |'' Leptosciarella (Leptosciarella) dimera'' ({{aut|Tuomikoski, 1960}})<ref name="SC226">{{aut|Mohrig, W.; Menzel, F.}} 1997: Revision der paläarktischen Arten von ''Trichosia'' Winnertz sensu Tuomikoski, 1960 (Diptera, Sciaridae). – Teil II. Gattungen ''Leptosciarella'' Tuomikoski, 1960 und ''Trichodapus'' gen. nov. ''Studia dipterologica'', '''4'''(1), 41–98.</ref>: 69-70; fig. 17}}
 | Wikispecies page name = Leptosciarella_dimera
 | ZooBank ID =urn:lsid:zoobank.org:act:B4805956-D1B2-4DB3-924C-6DCEBA7B4E00 
}}

==Type material==
Lectotype: ♂, in MZH, leg. Tuomikoski, 18.06.1958

===Type locality===
Finland, Vihti, Vihtijärvi

==Material studied==
'''Czech Republic:''' 1 ♂, Bohemia, Šumava mountains, Malá Niva, peat bog, photoeclector, Barták, 06.-07.1997, SDEI 2453; 
'''Finland:''' 2 ♂, Kb, Koli, Pielisjärvi, birch/spruce/aspen forest, sweep netting, Jaschhof, 11.06.2004, PKHH 6338, MZH 9068;
N, Lapinjärvi, spruce forest, photoeclector, Yakovlev, 25.4.-30.06.2005, MZH 9185; 
'''Germany:''' 7 ♂, ''Baden-Württemberg'', Bad Rotenfels, Bannwald Birkenkopf, Malaise trap, Doczkal, 3.4.-03.05.2003, PKHH 5065-5066, PDDM 141, PASS 141, ZSMC 2290-2291; 1 ♂, Blaubeuren, Tiefental, gorge forest, yellow pan trap, Sipple, 15.-22.04.2009, PKHH 7054; 7 ♂, Malsch, Wald NE Kieswerk Glaser, clearing, beech stump, Malaise trap, Doczkal, 19.3.-21.04.2010, PKHH 7886; 1 ♂ 1 ♀, Mössingen, Hirschkopf, fountain Hi 3, beech forest, W of landslip, sweep netting, Gerecke, 25.04.2012, PKHH 8004; 1 ♂, ''Mecklenburg-Vorpommern'', Klepelshagen, Buchenwald, sweep netting, Jaschhof, 23.04.1994, PKHH 5376; 3 ♂, Rosenthal near Strasburg, sweep netting, Jaschhof, PKHH 5314, 5315, 5317; 2 ♂, Rhineland-Palatine, Kirchheimbolanden, NSG Albertskreuz, Malaise trap, Doczkal, 11.4.-02.05.2002, PKHH 5092, 5098; 
''Saxony'', 1 ♂, Chemnitz, Zeisigwald, yellow pan trap, 01.-14.04.2008, Erlacher, MNC 36; 1 ♂, 15.04.-04.05.2008; 
'''Greece:''' 1 ♂, Procom, riverine forest along river Strymon; ''Populus alba'', ''Juglans regia'' and ''Corylus avellana'', Malaise trap, Ramel, 10.-16.03.2008, PKHH 7014; 
'''Sweden:''' 3 ♂, ''Bohuslän'', Ödsmal, Hällsberget, broad leaved deciduous forest, Malaise trap, Swedish Malaise Trap Project, 24.4.-25.05.2004, PKHH 5837, 7282, 7283; 7 ♂, ''Östergötland'', Omberg, Storpissan: old Norway spruce wood, Malaise trap, Swedish Malaise Trap Project, 3.3.-28.05.2005, NHRS 1838-1744; 13 ♂, ''Skåne'', Simrishamn, Stenshuvud National Park: Svabeholmsskog, hornbeam forest, Malaise trap, Swedish Malaise Trap Project, 22.5.-20.06.2005, NHRS 2977, 2978, PKHH 7253; 10 ♂, ''Småland'', Alsterbro, Mixed forest, Malaise trap, Swedish Malaise Trap Project, 30.4.-05.05.2005, PKHH 6684; 16 ♂, 15.-20.05.2005, PKHH 6600, 6608; 1 ♂, Bäckebo, Grytsjöns naurreservat, Old moisty haymaking meadow in forest edge, Malaise trap, Swedish Malaise Trap Project, 27.4.-18.05.2006, NHRS 3011; 1 ♂, 18.5.-15.06.2006, PKHH 6856; 
1 ♂, Gränna, Lönnemålen, next to old cellar; Norway spruce forest with big harvested ashes, Malaise trap, Swedish Malaise Trap, 28.4.-19.05.2004, PKHH 7949; 
'''Switzerland:''' 2 ♂ 2 ♀, Zurich, Sihlwald, window trap, Schiegg, 25.4.-11.05.1996, PKHH 1560, PWMP 1562; 2 ♂, photoeclector, Schiegg, 25.4.-23.05.1996, PKHH 2458; 1 ♂, 24.5.-19.06.1996, PKHH 2423; 2 ♂, window trap, Schiegg, 12.-23.05.1996, PKHH 1534; 1 ♂, 25.4.-11.05.1996, PKHH 1543; 
'''Ukraine:''' 1 ♂, Sakarpatje, near Rakhiv, sweep netting, Dimitrieva, 11.04.1990, PWMP 1771.

==Description (male)==
'''Head'''. Eye bridge 3 rows of facets. LW-index of 4<sup>th</sup> antennal flagellar segment 3–4.5; neck 0.25–0.38 of segment width; Transition of basal part to neck pronounced. Colour of neck unicolour. Antennal hairs as long as segment width; sparse; salient. Palps darkened; short; palpomeres 2, or 3. First palpomere thickened; with 4–5 bristles; with only some sparse sensillae. Second palpomere shortly oval. Third palpomere shorter than first segment, or as long as first segment. '''Thorax'''. Colour reddish. Notum unicolorous. Thoracic setae long and strong; dark. Mesonotum with some weaker central bristles. Posterior pronotum bare. Laterotergite bare. ''Legs''. Colour yellow. Hind coxae of same colour as femora, or darkened. Hairs on fore coxae black. Front tibia apically with a patch of setae. Front tibial organ not bordered. Tibial setae on hind legs weak, inconspicuous. Tibial spurs of equal length. Claws untoothed. ''Wings''. Wings slightly darkened; reduced, with weakly developed anal lobe. Wing membrane without macrotrichia. Wing venation weak, with faint m-base. M-fork of normal shape. R<sub>1</sub> inserting clearly before base of m-fork; posterior veins with macrotrichia; stM bare; cuA<sub>1</sub> and cuA<sub>2</sub> mainly with macrotrichia, or with a few macrotrichia; bM bare; r-m bare; bM:r-M 0.85–1.05; st-Cu:bM 0.45–0.6; r<sub>1</sub>:r 1.3–1.55; C:w 0.65–0.75. Halteres dark; of normal length. '''Abdomen'''. Abdominal setae strong and dense; dorsally dark; ventrally dark. Hypopygium concolour with abdomen; 0.55–0.7 × longer than wide. Base of gonocoxites with normal, weak hairs; gonocoxites broadly separated; inner margin of gonocoxites normally U-shaped; inner part of hypopygium scarcely setose; elongated setae on valves of hypopygium absent. Gonostylus elongate; 2–2.2 × longer than wide; Inner margin concave; apex equally rounded. Apical tooth present; 1.8–2.1 × longer than broad; normal. Awl-like setae normal; below apex present. Megasetae on inner part of gonostylus absent. Whiplash-hair absent. Tegmen 0.6–0.72 × longer than broad; rectangular with rounded edges; normal; Central process absent. Length of aedeagus/hypopygium 25–35 %; Aeadeagal apical structure present. '''Measurements'''. Body size 3–3.5 mm. Hind tibia 1.6–1.75 mm. Wing length 2.3–3 mm.

==Diagnosis==
''Trichosiopsis dimera'' is characterized by the very long antennae and rounded gonostyli. The antennae are still longer than in the similar ''[[Trichosiopsis cerifera]]'', which can otherwise be distinguished by the longer palpi and the more parallel gonostyli. The also similar species ''[[Trichosiopsis viatica]]'' has a more thickened first palpomere, shorter antennae and bright coxal hairs and halteres. The species was named “''dimera''” because the type specimen has two segmented palpi. Although the palpi are generally reduced in ''Tr. dimera'' most specimens observed have three-segmented palpi, only the two last segments often appear to be fused.

===DNA Barcoding===

The COI sequence is assigned to BIN {{BIN|ACD9636}} (average distance 0.79%, max. 1.85%, n=71, K2P: 12.12%). 
==Etymology==
''gr.'' di- = two; ''gr.'' meron = part. The name makes reference to two-segmented palpi.

==Ecology==
Like ''Tr. viatica'' ''Trichosiopsis dimera'' is commonly found in decaying wood. It is obviously widespread in European forests.

==Distribution==
Czech Republic<ref name="SC283">{{aut|Menzel, F.; Mohrig, W.; Barták, J.}} 2000: Sciaridae. In: J. Vanhara & M. Barták (Eds.), ''Diptera in an industrially affected region (North-Western Bohemia, Bilina and Duchcov Environs), I'', Folia Facultatis Scientiarum Naturalium Universitatis Masarykianae Brunensis (104). pp. 73-81.</ref><ref name="SC260">{{aut|Rudzinski, H.-G.}} 2000: Neue Trauermücken aus Mähren (Diptera: Sciaridae). ''Mitteilungen des Internationalen Entomologischen Vereins e. V.'', '''25''', 75–86.</ref>, 
Finland<ref name="SC043" /><ref name="SC470">{{aut|Salmela, J.; Vilkamaa, P.}} 2005: Sciaridae (Diptera) from central Finland: faunistics and taxonomy. ''Entomologica Fennica'', '''16''', 287–300.</ref><ref name="SC542">{{aut|Vilkamaa, P.; Salmela, J.; Hippa, H.}} 2007: Black fungus-gnats in deciduous forest habitat in northern Europe, with the description of ''Bradysia arcula'' sp. n. (Diptera: Sciaridae). ''Entomologica Fennica'', '''18'''(4), 226-231.</ref>, 
Germany<ref name="SC209">{{aut|Rudzinski, H.-G.}} 1995: Neue Nachweise von Trauermücken in Bayern (Diptera Nematocera, Sciaridae). ''Entomofauna'', '''16''', 277–279. [http://81.10.184.26:9001/pdf/ENT_0016_0277-0279.pdf PDF]</ref><ref name="SC275">{{aut|Hövemeyer, K.}} 1998: Diptera associated with dead beech wood. ''Studia dipterologica'', '''5'''(1), 113–122.</ref><ref name="SC731">{{aut|Heller, K.; Erlacher, S.I.}} 2012: Zehn für Sachsen neue Trauermücken aus dem Chemnitzer Zeisigwald (Diptera: Sciaridae). ''Veröffentlichungen des Museums für Naturkunde Chemnitz'', '''35''', 85–90.</ref>, 
Great Britain<ref name="SC446">{{aut|Menzel, F.; Smith, J.E.; Chandler, P.}} 2006: The sciarid fauna of the British Isles (Diptera: Sciaridae), including descriptions of six new species. ''Zoological Journal of the Linnean Society'', '''146''', 1-147. [http://www.online-keys.net/sciaroidea/2000_/Menzel_et_al_2006_Sciaridae_sp_n_checklist_GB.pdf PDF]</ref>, 
Greece, 
Latvia<ref name="SC226" />, 
Norway<ref name="GBIF">{{aut|GBIF}} [https://www.gbif.org/species/1486364 ''{{BASEPAGENAME}}'']</ref>, 
Slovakia<ref name="SC577">{{aut|Rudzinski, H.-G.}} 2009: Die Trauermücken des Poľana Biosphären-Reservats (Diptera: Sciaridae). ''Casopis Slezskeho zemskeho muzea, serie A'', '''58''', 39-46.</ref><ref name="SC732">{{aut|Rudzinski, H.-G.; Ševčík, J.}} 2012: Fungus gnats (Diptera: Sciaroidea) of the Gemer region (Central Slovakia): Part 3 – Sciaridae. ''Časopis Slezského zemského muzea'', '''61''', 143–157.</ref> , 
Sweden<ref name="SC565">{{aut|Heller, K.; Vilkamaa, P.; Hippa, H.}} 2009: An annotated check list of Swedish black fungus gnats (Diptera, Sciaridae). ''Sahlbergia'', '''15'''(1), 23-51.</ref>, 
Switzerland, 
Ukraine<ref name="SC226" />.

==Images==
{{Gallery | lines=3 | width=300
|1= File:Leptosciarella dimera Habitus KH5065.jpg|2= '''Figure 1.''' ''Trichosiopsis dimera'' male, habitus, scale 1 mm
|3= File:Leptosciarella dimera Hypopygium KH5317.jpg|4= '''Figure 2.''' ''Trichosiopsis dimera''  male, hypopygium, scale 0.1 mm
|5= File:Leptosciarella dimera Gonostylus KH5098.jpg|6= '''Figure 3.''' ''Trichosiopsis dimera'' male, gonostylus (ventral view), scale 0.1 mm
|7= File:Leptosciarella dimera Gonostylus dorsal KH5098.jpg|8= '''Figure 4.''' ''Trichosiopsis dimera'' male, gonostylus (dorsal view), scale 0.1 mm
|9= File:Leptosciarella dimera Tegmen KH5317.jpg|10= '''Figure 5.''' ''Trichosiopsis dimera'' male, aedeagal complex, scale 0.1 mm
|11= File:Leptosciarella dimera Antenna KH6608.jpg|12= '''Figure 6.''' ''Trichosiopsis dimera'' male, 4<sup>th</sup> antennal flagellar segment, scale 0.1 mm
|13= File:Leptosciarella dimera Palpus KH7886.jpg|14= '''Figure 7.''' ''Trichosiopsis dimera'' male, palpus, scale 0.1 mm
|15= File:Leptosciarella dimera Wing KH5098.jpg|16= '''Figure 8.''' ''Trichosiopsis dimera'' male, wing, scale 1 mm
}}

==References==

<references />