Indochinomyia, Papp, László, 2016

Papp, László, 2016, A New Genus Of Phyllomyzinae (Diptera: Milichiidae) From Laos And Vietnam, Acta Zoologica Academiae Scientiarum Hungaricae 62 (4), pp. 347-354 : 348-350

Indochinomyia gen. n.

( Figs 1–7)

Typespecies: Indochinomyiaviet sp. n., bypresentdesignation.

Gender: feminine.

Additional species: Indochinomyia lao sp. n.

Diagnosis. Medium-sized (2.8–3.25 mm) shinyblackflies ( Fig. 1) with clear, possiblyhyaline, wingandsimplelegsinthesubfamilyPhyllomyzinae. Headinprofilesubquadrate, verticaldiameterofeyelessthan 1.5 timesas longashorizontaldiameter, epistomanotextendeddorsally, vibrissabelow lowestedgeofeye, postocellarsetaeverylong, apicescrossing, basisternum small, wing without subcostal notch, veins R 4+5 and M 1+2 not converging towardswingtip, cubitalcellterminatesacutely (i.e. notrounded), hindbasi- tarsuswithaposteriorcombofthinsharpsetae.

Description. Head. Occiputonlyslightlyconcave. Proboscisnotelongate, labella shorterormuchshorterthanhead. Antennaenotfarfromeachother ( Fig. 4). Firstflagel- lomereextremelylargeinfemale ( Figs 2–3), mostprobablyalsoinmale, i.e. firstflagel- lomeremuchlargerthanpedicel. Actually 3 lateroclinatelongorbitalpairs, posteriorone farfromthe 2 anteriorpairsandclosetoinner (medial) verticalseta, orbitalplatestrongly obliqueandanteriororbitalsetamuchmedialtoandslightlyanteriortoposteriorfrontal seta ( I. viet ), or, orbitalplatelessobliqueandfusedwithfrontalplateintoaverybroad shiny rim of eye ( I. lao , Fig. 4); some other thin frontal setae present. Frontal vitta (interfrontalstripe) finelyhatched ( Fig. 4) broad, terminatesbroadlyabovelunule ( Fig. 4) with apairofsupra- antennalsetaemostanteriorly, lunulesmallwithapairofshortsetae. No interfrontalsetaeoronlyafewunpairedhairsininterfrontalposition. Ocellicompara- tivelylarge, distanceofhindocellilessthan 2 timeslargerthandiameterofforeocellus. Scapeverysmall, pedicelwithalongdorsalapicalseta. Firstflagellomerewithoutlong cilia, aristawithscatteredveryshort (0.015 mm) rays. Vibrissalanglesharp, mouthmargin more or less protruding ( Figs 2–3).

Thorax. Stronglyconvex, mesonotumstronglyshiny. Only 1 postpronotalseta, 1 long presutural, 2 notopleural, 1–2 posteriordorsocentral, 2 supra- and 2 post-alareach (1 very largeposteriorsupra- alar, 1 strongpost-alarinintra- alarposition) pairsofsetae. 2 pairs ofscutellarsetae, nodiscalscutellarsetulae. Acrostichalmicrochaetaenumerousandnot orderedinregularrows, emergingfromsmallswellings. Noenlargedprescutellaracros- tichalpairpresent.

Wing. Costawith 2 costalbreakssimilarlytootherMilichiidae, humeralbreakasfar from humeral vein as the length of humeral vein, costal vein extending to vein M 1+2. Third andfourthcostalsectionsaboutequallylong, secondcostalsection 6 to 7 timesaslongas third section. No notch or stronger fringe on costa. Cross- vein R-M at about middle of dis- calcell. DistalsectionofMre 3+4 acheswingmargin. Alularatherlarge (almostasbroadas discalcell), withmediumlongmarginalsetae; otherwiseasinthediagnosis.

Legs. Simple, midtibiawithalongstraightapicalspur. Hindbasitarsuswithacompletecombofstraightratherthinshortsetae.

Femaleabdomenandgenitalia. Abdomennottelescopised (i.e. intersegmentalmembranesshort). Abdominaltergites 1+2 occupies 1/3 ofabdominallength. Preabdominal sternites only 1/6 width of tergites or so. Tergite 7 and tergite 8 not divided, tergite 8 seems slightlyasymmetrical ( Fig. 7). Cercusverysmallobliquewithmedium-longsetaeonly ( Figs 6–7), epiproct (supra- analplate, tergite 10) shortandverybroadwith 1 pairoffinese- tae ( Fig. 6), hypoproct (subanalplate, sternite 10) large ( Fig. 7) althoughweaklysclerotised.

Maleunknown.

Etymology. The name of the new genus composed of the name of the territory of the collectionofitsspecies (Indochina) andoftheGreek‘ myia ’ (= fly).

Discussion. This new genus keys to couplet 10 in Brake’s key to genera of Milichiidae (seeDiagnosis): Indochinomyia gen. nov. isnotcloselyrelatedto Borneomyia Brake, 2004 . Although the male sex has been unknown, it seems improbablethatthemaleflagellomerewouldbelargerthanintheholotype females. Hindfemuriswithoutafemoralorgan. Whenreachingcouplet 10, none of the two branches fit to the new genus: Occiput only slightly concave, firstflagellomeremuchlargerthanpedicel, lunularpairofsetaeminute. The comparativelylargeshinyblackbody ( Fig. 1) makesthenewgenusconspicu- ousatafirstglance.

After all, I think the closest relative of Indochinomyia gen. n. is the genus Phyllomyza Fallén. However , ithasnointerfrontalsetae (orafewscatteredhairs there), femalepostabdomenisnottelescopingatall, neithertergite 7 nortergite 8 is divided (the latter is slightly asymmetrical but it is not sure that is a general feature), hypoproct (subanalplate) isverylarge ( Fig. 7) contrarilyto Phyllomyza females, epiproct (supra- analplate) veryshortbutbroad. Itisamatterof coursethatadiscoveryandstudyofthemalesexwillwidenthedifferences.