Heteropterna (Heteropterna s. str.) cuneata Wang et Huang, 2021

Wang, Qingyun, Qi, Lei, Wu, Hong & Huang, Junhao, 2021, Two new species of Heteropterna Skuse, 1888 (Diptera: Keroplatidae) from China, Zootaxa 4985 (2), pp. 277-284 : 278-279

Heteropterna (Heteropterna s. str.) cuneata Wang et Huang sp. n.

( Figs 1–2 )

Diagnosis. This new species resembles H. annulipes (Colless) in appearance by having similar wing pattern, but can be recognized by the cercus tapering to the apex, the external lobe of gonostylus apically rounded in ventral view, and the gonocoxites with posterior 1/5 split into halves in the terminalia ( Figs 2i–k ). In H. annulipes , the cercus is reniform, the external lobe of gonostylus has a pointed end in ventral view, and the gonocoxites are fused posteriorly in the terminalia ( Colless 1966: Figs 1a–c ).

Type material. Holotype. Male, CHINA: Guizhou Province, Mt. Fanjing (27.8° N, 108.62° E), 750 m, 5.VI– 4.VII.2020, coll. Fanliang Liu, slide no. FJS-11-20.

Description. Male ( Fig. 1 ). Body length (without antennae) 5.5 mm. Wing length 3.2 mm. Length of terminalia 0.56 mm.

Head dark brown. Compound eyes ( Fig. 2a ) hemispheric, occupying most area of head, bearing dense pubescence on surface. Three ocelli ( Fig. 2b ) lying between upper edges of eyes, arranged in an inverted triangle, with lateral ones about three times of median one in diameter. Mouthparts ( Fig. 2a ) reduced, palpus two-segmented and porrect, labrum subtriangular, labellum has bushy setae outside. Antenna ( Fig. 2c ) pectinate and laterally compressed, slightly longer than head width; scape and pedicel subtrapezoid, covered with dense microtrichia laterally, having setae in different length dorsally and ventrally; flagellum 14-segmented and comb-like, bearing dense microtrichia laterally, with a few setae dorsally and ventrally; flagellomeres 1–11 brown (except 7th and 11th segment partly yellowish white), flagellomeres 12–14 yellowish white, with last one somewhat dark apically.

Thorax ( Figs 2d–f ) brown. Prothoracic spiracle membranous, elliptical. Anepisternum dark brown and subtriangular, with sparse setae. Mesonotum brown, middle streak dark brown and cuneiform, with yellowish brown stripes along lateral sides. Scutellum fuscous, subrectangular. Mediotergite yellowish brown and subtriangular, with medial membranous area inverted triangular. Laterotergite fuscous brown, suboval. Halter length 0.38 mm; stem translucent, with setae anteriorly; knob dark brown, with sparse setae anteriorly.

Wing ( Fig. 2g ) pale brown, having dense microtrichia on surface, outer and posterior margin with short cilia. Fuscous stripe along costal margin, about 1/4 width of wing, extending from base to end of costa. Hyaline spots irregular, with a smaller medial spot from end of Sc obliquely outward to above middle of R, and a larger apical spot from end of R 2+3 obliquely outward to above bottom margin of stripe. Veins brown to dark brown, with two rows of microsetae on C, and a row of microsetae on R 1 and R 4+5. Vein C stops at 5/12 of R 4+5 -M 1. M 1 and M 2 weaker than other veins, with M 1 ending at outer margin and M 2 ending far from outer margin. CuA curved backward at middle. False vein close to CuA, with free end. Vein r-m degenerated and weakly sclerotized.

Legs ( Fig. 1 ) yellowish white to dark brown. Coxae dark brown, covered with setae densely. Femora yellowish brown, scattered with setae. Tibiae and tarsi light brown, bearing thick microtrichia.

Abdomen ( Fig. 2h ) brown, covered with dense setae. Tergites light brown. Sternites dark brown, with paired subelliptical hyaline spots on sternites 2 to 4.

Terminalia ( Figs 2i–k ) brown. Tergite 9 subtrapezoidal, concave both anteriorly and posteriorly, covered with setae densely. Cercus setose dorsally, wide basally, tapering to posterior end, with distal half slightly curved inward. Gonocoxites ventrally with anterior 4/5 fused, posterior 1/5 spilt into halves; posterior protuberance subtriangular, with stout setae ventrally. In ventral view external lobe of gonostylus thinly digitate, rounded terminally, slightly shorter than width of gonocoxite, having dense long bristles laterally; internal lobe of gonostylus corniform, about 2/3 length of external lobe, with short setae inside and long bristles outside. In lateral view dorsal lobe of gonostylus subtriangular, covered with dense setae.

Female. Unknown.

Etymology. The name of this species is from the Latin cuneatus (cuneiform), in reference to the cuneiform streak at middle of mesonotum; adjective in genitive case.

Figures

FIGURE 1. Male adult of Heteropterna (Heteropterna) cuneata sp. n., holotype, dorsolateral view.

FIGURE 2. Heteropterna (Heteropterna) cuneata sp. n., holotype. a–b, head (a, frontal view; b, dorsal view), antennae removed; c, antenna; d–f, thorax (d, dorsal view; e, posterior view; f, lateral view); g, wing; h, ventral view of abdomen; i–k, terminalia (i, ventral view; j, dorsal view; k, lateral view). Slide No. FJS-11-20.