Helina umbratiseta Xue, 2025

Li, Siyu, Xue, Wanqi, Nihei, Silvio S. & Zhang, Chuntian, 2025, Four new species of Helina Robineau-Desvoidy from far northwestern China (Diptera: Muscidae), Zootaxa 5719 (2), pp. 207-227 : 222-225

Helina umbratiseta Xue sp. nov.

( Figs 7–8 )

urn:lsid:zoobank.org:act:

Description. Body length 7.0– 7.2 mm.

Male. Head. Eye with slightly dense long ciliae, most ciliae 1.2–1.3x as wide as frons. Frons about equal to the anterior ocellus, slightly narrower than postpedicel, frontal vitta black, 6–7 pairs of frontal setae, situated on lower half of frons, without orbital setae; fronto-orbital plate adjacent at the narrowest point, fronto-orbital plate and parafacial with gray white pruinosity, parafacial about 1.5x as wide as postpedicel; gena with gray pruinosity, genal setulae black, height about 1/4 of eye height, anterior margin of gena with one row of slightly upcurved setae. Antenna black, postpedicel about 3x as long as broad; arista short plumose, the longest hairs about 1/2 as wide as postpedicel; epistoma not protruding, vibrissal angle situated behind frontal angle; prementum with minority pruinosity and luminance, prementum about 2.5x as long as broad; palpus black, longer than prementum; labellum normal size, posterior margin without teeth.

Thorax. Ground colour black, scutum with light gray brown vitta in the middle and four black vittae, the inner vitta (between acr rows) approaching scutellum, a narrow pale pruinose strip between the inner vitta and the outer vitta. Scutellum black, lateral and ventral surfaces bare, apical scutellar setae long and basal scutellar setae longer then apical setae; acr 0+1, dc 2+3, the distance from the first seta to the second one large, and the distance from the second to the third small, the first distance about 2.2x the second one; ial 0+2, pra hair-like, notopleural bare; prosternum, mid-dorsal excavation of proepisternum, anepimeron, meron and katepimeron all bare, anterior anepisternal seta 1, katepisternal setae 2+2; spiracles brown.

Wing. Wing slightly transparent, veins brown, basicosta brown, tegula black, costal spine developed, subcosta bend in a bow shape, Rs node bare, M straight, r-m without dark spot; dm-cu curved, without dark spot, calypter yellow, lower calypter tongue-like, halter yellow, but brown basally.

Legs. All black; fore tibia without median p; mid femur without developed av, with median basal pv, with 2 sub-apical ad and complete median pv row; mid tibia without ad and sub-basal pv, with 3 p; hind femur with complete av row, which became longer toward the top, without pv, hind tibia with a row long av, a row of fine pv setulae, with slightly shorter fine v setulae, 2 sub-median ad, without apical pv; each tarsi longer than tibiae, fore pulvillus longer than claw, fore pulvillus approximate equal to fifth tarsomere, fore leg subequal to hind leg.

Abdomen. Ground colour black, ovoid in dorsal view, with dense gray pruinosity, without shifting patches laterally; tergites 3 and 4 respective with a pair of long trapezoid dark brown patches, and in basal half of tergite 4 light brown and become narrow; with a middle vitta between the two patches and sparse setae, setae with dark patches on base; each tergites with complete posterior marginal setae; sternite 1 bare.

Terminalia. Cerci wide, longer than its length, with inconspicuous inner and outer lobe, the inner lobe is larger than the outer lobe. Surstylus slightly thick, with a protrusion near the apex, and with several small hairs in ventral surface. Pregonite slightly shorter than the postgonite.

Female. Unknown.

Type material. Holotype ♂, CHINA: Xia Pagoda, Zhaosu County, Yili Kazakh Autonomous Prefecture , 2300–2500 m, 42°40′30N, 80°36′08E, Xinjiang Uygur Autonomous Region , 5.vii.2018, Chuntian Zhang leg. ( SYNU2006124 ) . Paratypes: 2 ♂,same as holotype ( SYNU2007498 , SYNU2007485 ).The specimen SYNU2007498 was dissected for description and illustration of male terminalia .

Etymology. The specific name refers to the distance from the first posterior dorsocentral seta to the second one large, and the distance from the second to the third small, the first distance about 2.2x the second one, it is similar in appearance to posterior dorsocentral seta 4, where the second seta was missing. Latin word “ umbrat ” means covert, “ seta ” means seta. It is a female noun in the nominative singular.

Distribution. China ( Xinjiang).

Remarks. The new species is similar to Helina xingkaiensis , but differs from the latter as follows: frons about 2x the width of postpedicel, arista long plumose, the longest hairs about 1.2x as long as postpedicel width, prementum about 2.0x as long as broad. dc 2+4, mid tibia with 3 p, hind femur with complete hair-like pv row.

Figures

FIGURE 7. Helina umbratiseta Xue sp. nov., male. A–B. Dorsal and lateral habitus. C. Head in anterior view. D. Sternite 5. E. Cerci in posterior view. F. Terminalia, pregonite and postgonite. Scale bars: A–C, 1 mm; D–F, 0.1 mm.

FIGURE 8. Helina umbratiseta Xue sp. nov., male. A. Abdomen in dorsal view. B. Sternite 5. C. Cerci in posterior view. D. Epandrium, cercus and surstylus in lateral view. E. Terminalia. F. Pregonite and postgonite. Scale bars: A, 1 mm; B–F, 0.1 mm.