Thinobius bicolor Joy, 1911

Makranczy, György, 2014, Synonymies In The Holarctic Thinobius Major And Linearis Species Groups (Coleoptera: Staphylinidae: Oxytelinae), Acta Zoologica Academiae Scientiarum Hungaricae 60 (1), pp. 13-38 : 26-29

Thinobius bicolor Joy, 1911

( Figs 4 , 16 , 29–31 )

Thinobius bicolor JoY, 1911 : 10.

Thinobiuslinderianus SCheeRpeltZ, 1966: 257. (newsynonyminSChülKe & MAKRANCZY 2011)

Examinedtypematerial – Thinobiusbicolor Joy – Lectotype (f), bypresentdesigna- tion: “Type [redframeddisc] \ Dalwhinnie; N.H.J. 1.5.[= V.][19]10 \ Brit. Mus.; 1924-468. \ Thinobius ; bicolor. Joy; mType \ EMM 1911 \ bicolorJoy \ Lectotypus; Thinobius ; bicolor Joy ; des. Makranczy, 2003 / Thinobius ; bicolorJoy; det. Makranczy, 2013” ( BMNH); [For typesof Thinobiuslinderianus, seeMakranczy & Schülke, 2001: 189.].

Othermaterial – GREATBRITAIN: Scotland , Dumfries , RiverNith , April 1870?, leg. D. Sharp (1255A) (1, coll. Champion, BMNH, 1, coll. Tottenham, BMNH); Harburn, near Carsfairs, April 23, 1866, leg. D. Sharp (1025) (10, BMNH) ; Ranvoch , May 2-9, 1866, leg. D. Sharp (1030) (1, BMNH, 1, coll. Sharp, BMNH) ; [ Ranvoch ?], May 1866, leg. D. Sharp (2, coll. Power, BMNH) ; Palmont [Polmont, Stirling], April 19-20, 1866 leg. D. Sharp (1023) (2, coll. Champion, BMNH, 3, coll. Sharp, BMNH), GribtonBridge, April 30, 1868, leg. D. Sharp (1128) (1, coll. Sharp, BMNH) , SeatatDruidhillnearEccles, May 11, 1869, leg. D. Sharp (1184) (1, coll. Sharp, BMNH) ; Dumfries , April 1867, leg. D. Sharp (1056] (1, coll. Sharp, BMNH) ; CavinWater , May 1, 1867 leg. D. Sharp (1057) (1, coll. Sharp, BMNH) ; MortonMainsApril 12, 1868 leg. D. Sharp (1123) (1, coll. Sharp, BMNH); Cumberland , GreatSalkeld, 10.IV.1909, [leg.] H. Britten (1, coll. Champion, BMNH) ; Perthshire, Kinbuck [56.2213° N, 3.9481° W], 18.IV.1982, leg. R.M. Lyszkowski (2, HNHM) ; GERMANY: Rhein- land, Nahe , Heinzenberg, Kellerbachtal, 19.IV.1988, leg. P. Wunderle (1 m, 1 f, HNHM) .

Redescription – Measurements (in mm, n = 4): HW = 0.30 (0.295 –0.315); TW = 0.31 (0.305–0.33); PW = 0.32 (0.31–0.34); SW = 0.34 (0.32–0.35); AW = 0.40 (0.38–0.45); HL = 0.24 (0.24–0.25); EL = 0.08 (0.08–0.09); TL = 0.11 (0.10–0.12); PL = 0.26 (0.25–0.27); SL = 0.40 (0.38– 0.44); SC = 0.37 (0.34–0.41); FB = 0.92 (0.88–1.00); BL = 1.94 (1.72–2.15). Body ( Fig. 4 ) in fully colouredspecimensslightlybicoloured (seealsoremarks). Head, pronotumandabdomen darkbrown. Elytralighttomediumbrown, scutellarareasometimesbroadlydarker. Legs, mouthpartsandantennaelighttomediumbrown, firsttwoantennomeressomewhatlight- er, terminalthreesegmentsoftendarker. Allmainbodypartswithveryfinecoriaceous microsculptureintermixedwithpunctation, makingbodymoderatelylustrous. Puncta- tionveryfineandratherdense, lessdistinctthaninprevious 3 species; headstrongest, pronotumfinerandmoredense, abdomensimilarbutevenlessdistinct, elytrahardlydiscrenible, surfacedominatedbymicrosculpture. Pubescenceonforebodyratherdepressed, short, fineanddense (onelytrathemostdense), onabdomensomewhatlessdenseand longerhairs, apicesoftergiteswitharowoflonghairs, abdominalsidesandapexwitha fewdarkerandstrongerbristles. Strongdarkbristleonoutersideofsupraantennaltuber- cleatanteriorborderofeyeandonposterioredgeofvertexadjacenttotemples, similar onesrightbehindanteriorpronotalcornerandonsideat 3/5 length. Setationonhead mostlymediallydirected, asalsoonpronotumbutanterioronposteriorpronotaledgeand antero-medialonasmallerspotinmiddlehindpartofdisc. Elytraandabdomenwithposteriorlydirectedhairs. Antennae, legsandmouthpartswithveryshort, notconspicuous setation, exceptforthestiff, darkermid-tibialhairsondonesnearapicesoffemora. Sides ofelytrawiththreesuchstiffsetaeaboutequallydistributedonlengthofside .

Headslightlywiderthanlong, templesusuallysomewhatwideningthennarrowinginagentlecurve, weaklyroundedonposteriorpart. Middleofvertexwithaslight transversalimpression. Anteriorborderofneckisstronglymarkedwithashiny, arched, deepgroove. Frontoclypealsutureappearingasfine, oftenshiniergrooveanddarkline connectingsupraantennaltubercles, similarlydarkerspotssituatedatbothsidesonmiddleofvertex. Supraantennaltuberclesmoderatelydeveloped, separatedfromvertexby longitudinalimpression. Antennaemediumlong ( Fig. 16 ), 6thantennomereappearingas wideasadjacentones.

Pronotumweaklytransverse, 1.30× widerthanlong, justatinybitwiderthanhead, someverygentleimpressionsatsideofunmarkedpronotalmidlineespeciallyinthemiddleofdisc. Anteriorcornersratherweaklyrounded, posteriorcornersverybroadly, sides gentlyarched. Pronotalmarginalbeadvisibleonposteriorandlateralmargins, anterior marginslightlypulledaheadinmiddlewithvisiblemarginalbead. Scutellumsmall, if exposed, shinierthanadjoiningareas. Elytraratherlong, oneelytronabouttwiceaslong asbroad, flatandparallel-sided (verygentlydilatingposteriorly). Shouldersmoderately developed. Alongsuturewithouteventracesofmarginalbead; suturalcornersmoderately 35, 0.10 mm for Figs 37, 39 , 0.12 mm for Fig. 38 , 0.14 mm for Fig. 40 , 0.18 mm for Fig. 34.

broadlyrounded. Legs ofmediumlength, tarsallobessmallandthin, inconspicuous, tibiae ratherfusiform, appearmuchwiderinmiddlethanatends.

Abdomenveryweaklyfusiform, sidesmoreorlessstraightandparallel; widestin themiddle, justveryslightlylesswidethanelytraatbroadestpoint. Posteriormarginof tergiteVIIwithpalisadefringeandposteriorcornersbroadlyrounded. Primaryandsecondarysexualfeatures: Sexesnotappearingdifferentinregulardorsalview. Posteriorcornersof tergiteVIII (similarinbothsexes) slightlypulledout, posterioredgegentlyconcave, arched inbetween. MalesterniteVIIIasinFig. 29 , tergiteIXasinFig. 30 , sterniteIXasinFig. 31 .

Distribution – Averyincompletelyknownspecies, mainlyduetoitsdifficultsepara- tion from Thinobius bunneipennis Kraatz, 1857 , but seems to be present in the British Isles andWesternEurope.

Remarks – The type of T. bicolor is a female and it belongs to a pair of sibling species ( T. bicolor and T. brunneipennis ) where females cannot be distin- guishedatthepresentstateofourknowledge. Toassurethecorrectnessofthe identificationofthisspecies, thewholehistoricalBritishunidentifiedmaterial inBMNHwaschecked. Themalesinthismaterial, withoutexception, proved to belong to the taxon previously treated as T. linderianus (see MAKRANCZY & SChülKe 2001: 189). Therefore, itseemsthatthesiblingtaxon, T. brunneipennis (intheidentityfixedbytheneotypedesignationinthepreviouslycited article) doesnotoccurinBritain. Asthevalidnameofthespeciesis T. bicolor , aspecialnoteaboutthereliabilityofcolourcharactersisfeltinplacehere. Itisveryusualtohavecertainbodypartslighter, brighterinfullycoloured specimens, whileteneralornotfullycolouredspecimensremainmoreor lessunicolorous. Agoodexampleofthisisarecentlydescribedspecies, T. gurzoeszterae Makranczy, 2009 , wherethefemaleholotype ( Fig. 55 ) isfully colouredwithrathercontrastingbodyparts, whereasthemaleparatypeappearsunicolorous. Asimilarsituationexistswith T. bicolor and T. brunneipennis , wherespecimenswithbrightelytraoccasionallyoccur, butitisnottrue forallspecimensandnotlinkedtogeographicaldistribution.

Figures

Figs 1–6. Forebodies of Thinobius species: 1 = T. major Kraatz, 1857, 2 = T. angusticeps Fauvel, 1889, 3 = T. procerus Eppelsheim, 1893, 4 = T. bicolor Joy, 1911, 5 = T. petzi Bernhauer, 1908, 6 = T. micros Fauvel, 1871. Scales: 0.07 mm for Fig. 6, 0.10 mm for Figs 2, 4–5, 0.14 mm for Figs 1, 3.

Figs 13–26. Antennae of Thinobius species: 13 = T. major Kraatz, 1857, 14 = T. angusticeps Fauvel, 1889, 15 = T. procerus Eppelsheim, 1893, 16 = T. bicolor Joy, 1911, 17 = T. petzi Bernhauer, 1908, 18 = T. micros Fauvel, 1871, 19 = T. paramicros sp. n. 20–22 = T. major Kraatz, 1857, male, 20 = sternite VIII, 21 = tergite IX, 22 = sternite IX. 23–24 = T. angusticeps Fauvel, 1889, male, 23 = tergite IX, 24 = sternite IX. 25–26 = T. procerus Eppelsheim, 1893, male, 25 = tergite IX, 26 = sternite IX. Scales: 0.05 mm for Figs 13, 15, 0.06 mm for Figs 14, 16–17, 26, 0.07 mm for Fig.

Figs 27–33. 27 = T. angusticeps Fauvel, 1889, male sternite VIII. 28 = T. procerus Eppelsheim, 1893, male sternite VIII. 29–31 = T. bicolor Joy, 1911, male, 29 = sternite VIII, 30 = tergite IX, 31 = sternite IX. 32–33 = T. petzi Bernhauer, 1908, male, 32 = tergite IX, 33 = sternite IX. Scales: 0.10 mm for Fig. 33, 0.11 mm for Fig. 32, 0.12 mm for Figs 30–31, 0.135 mm for Fig. 27, 0.15

Figs 34–40. 34 = T. petzi Bernhauer, 1908, male sternite VIII. 35–37 = T. micros Fauvel, 1871, male, 35 = sternite VIII, 36 = tergite IX, 37 = sternite IX. 38–40 = T. paramicros sp. n., male, 38 = sternite VIII, 39 = tergite IX, 40 = sternite IX. Scales: 0.08 mm for Fig. 36, 0.09 mm for Fig.

Figs 54–55. 54 = T. paramicros sp. n., habitus, 55 = T. gurzoeszterae Makranczy, 2009, habitus.