Leskia latisurstyla Zhang & Dong, 2024

Dong, Ruiqing, Li, Junjian, Yang, Hui & Zhang, Chuntian, 2024, Three new species and two newly recorded species of Tachininae from Tibet, China (Arthropoda, Insecta, Diptera, Tachinidae), ZooKeys 1191, pp. 215-235 : 215

Leskia latisurstyla Zhang & Dong sp. nov.

Fig. 1

Material examined.

Holotype: China • ♂ (SYNU-E 19381); Tibet (= Xizang); Linzhi, Bayi Town ; 29.7425°N, 94.3189°E; 3000 m elev.; 12.VIII.2013; Q. Wang leg. Paratype: 1♂ (SYNU-E 21575; NW Yunnan; Gongshan County, Dimaluo Village ; 27.7470°N, 98.6723°E; 1600 m elev.; 19.V.2007; X.Y. Liu leg.

Etymology.

The specific epithet is derived from the characteristically wide surstylus in caudal view of this species; it is composed from the Latin adjective lati and the noun surstylus.

Diagnosis.

This species is similar to L. flavitegula Zhang, but it is distinguished from the latter in the height of the gena, which is about 1/4 of eye height, the longer prementum, which is at least 6.5 times as long as wide apical 4/5 of postpedicel dark brown in male, and palpus which is slightly longer than antenna. Discal scutellar setae are slightly shorter than the scutellum length; anepimeral setae 2, katepisternal setae 3; tegula dark brown except for the yellow base. Surstylus wider and bluntly roundedat apex in caudal view, postgonite narrower at middle.

Description.

Male. Body length 10.0 mm.

Head (Fig. 1C, D ). Eye bare. Frontal vitta brownish black, ground colour of fronto-orbital plate, parafacial, and face dark yellow; fronto-orbital plate and parafacial with thin, grayish-yellow pruinosity; face with grayish-white pruinosity. Occiput with grayish-yellow pruinosity. Lunule dark yellow, with grayish-yellow pruinosity. Palpus reddish yellow on apical half and dark on basal half. Prementum gleaming black. Antenna with scape, pedicel, and basal 1/5 of postpedicel reddish yellow; apical 4/5 of postpedicel and basal 4/5 of arista dark brown. Frons slightly widened anteriorly, about 4/7 of eye width at narrowest point; frontal vitta at anterior ocellar point slightly narrower than fronto-orbital plate. In anterior view parafacial at middle about as wide as postpedicel, lower margin of face protruding forward in lateral view, vibrissa at level of lower margin of face. Fronto-orbital plate with fine hairs, parafacial bare. Genal height about 1/4 of eye height; 16-17 pairs of crossed frontal setae, with upper and lower frontal setae smaller than other frontal setae, lowest frontal setae at nearly level with apex of pedicel, 2 to many proclinate ocellar setulae, longest one slightly shorter than upper frontal setae, inner vertical setae strong, crossed, about 0.65 times as long as eye height, outer vertical seta outward, about 0.58 times as long as inner vertical seta, a pair of smaller postocellar setae. Occiput only with 2-3 rows of black hairs below postocular setae except for white hairs, and with a row of subvibrissae below vibrissa, which 0.30-0.35 times as long as vibrissa. Antenna short; scape erect, forming closed angle to pedicel; postpedicel about 3 times as long as wide and about 2.6 times as long as predicel; arista bare, thickened at least on basal 1/5. Palpus longer than antenna. Prementum 6-7 times as long as wide. Proboscis medium-sized.

Thorax (Fig. 1A, B ) dark brown, with dense, grayish-yellow pruinosity on dorsum; anterior spiracle yellow; posterior spiracle reddish yellow. Thoracic dorsum with 4 dark longitudinal vittae; broad outer and narrow inner vittae on presutural scutum; distance between inner and outer vittae about 5.5 times as wide as inner vitta; inner vitta extend to scutoscutellar suture. Prosternum bare, about 1.6 times as long as wide; proepisternum bare; 3 postpronotal setae nearly arranged in a straight line; 3 presutural and 2 postsutural acrostichal setae, 3 presutural and 3 postsutural dorsocentral setae, 3 postsutural intra-alar setae, prealar seta about as long as notopleural seta, 2 supra-alar setae, anterior one stronger, 1 upward proepimeral seta, upper anepisternum with 1 shorter and upward seta, a row of 6-7 outward setae behind anepisternum, 2 anepimeral setae, a tuft of fine hairs around it, 3 katepisternal setae, 3 anterior setae set in straight line, katepimeron (= barette) with 4-5 hairs on anterior half, anatergite and katatergite bare. Scutellum with semi-erect setulae at medialy dorsal surface and 2 discal setae; apical scutellar setae crossed, upward, as long as basal scutellar setae; lateral scutellar setae slender, about 1/2 as long as subscutellar seta.

Wing pale brownish yellow, hyaline. Tegula dark brown except for yellow base; basicosta yellow. Lower calypter yellowish white, with short fringe on outer margin; halter yellowish white at middle, reddish yellow in both apexes, with 5-7 fine hairs at apical 1/4; costal spine absent or short; vein 1st and 2nd costal sections with fine hairs ventrally; relative lengths of 2nd, 3rd, 4th costal sectors approximately as 1:2:1; base of vein R4+5 with 2-3 short setae dorsally and ventrally; vein M from dM-Cu crossvein to its bend about 1.3 times distance between the bend and wing posterior margin; vein M nearly parallel with vein R4+5.

Legs slender, yellow to reddish yellow except tarsi black-brown, with thin, grayish-white pruinosity. Fore claw and pulvillus longer than 5th tarsomere, fore tibia with 2 posterior setae, 1 preapical anterodorsal seta, 1 preapical dorsal, and 1 preapical posteroventral setae. Mid tibia with 1 anterodorsal, 1 ventral, and 2 posterior setae. Hind tibia with a complete row of anterodorsal setae, 4-5 posterodorsal setae, and 3 anteroventral setae.

Abdomen long ovate, mostly yellow, with yellowish-gray pruinosity, with a dark-brown, broad, trapezoidal median marking on syntergite 1+2 and tergite 3; tergite 4 with pruinosity on basal 1/5 and dark brown on posterior 4/5; tergite 5 brown. Syntergite 1+2 medially excavate to hind margin and with a pair of lateral marginal setae; tergite 3 with a pair of lateral marginal and 2 median marginal setae; tergite 4 and 5 each with a row of marginal setae; tergites without discal setae. Posterior sternites 2-4 each with 2 posterior setae.

Sternite 5 and male terminalia as Fig. 1E-H . In ventral view, sternite 5 nearly square, V-shaped median cleft about 2/5 of sternite length; lateral lobe bluntly rounded apically. In caudal view, cerci slender and narrowed at apical 2/3 and pointed apically, and surstylus slightly longer and bluntly rounded apically. In lateral view cerci slightly bent ventrally and surstylus wide, bluntly rounded at apex. Distiphallus with some small spines on foot-like membranous part and contacted with sclerotized part. Pregonite long, postgonite short and narrow at middle.

Female. Unknown.

Distribution.

China (Tibet, Yunnan; Fig. 8 ).

Figures

Figure 1. Leskia latisurstyla sp. nov. A, B ♂, bodies, dorsal and lateral views C, D ♂, heads, anterior and lateral views E sternite 5, ventral view F phallus (aedeagal apodeme, hypandrium, pregonite, postgonite, basiphallus and distiphallus) of male, lateral view G, H cerci, surstyli and epandrium of male, caudal and lateral views.

Figure 8. New distribution records of Tachininae from Tibet, China. 1, 2 Leskia latisurstyla Zhang & Dong, sp. nov. 3 Trichoformosomyia cuonaensis Zhang & Li, sp. nov. 4 Tachina jilongensis Zhang & Dong, sp. nov. 5 Nemoraea javana (Brauer & Bergenstamm, 1895) 6 Nemoraea echinata Mesnil, 1953.