Neoloxotaenia gracilis

Liu, Xiaoyan & Yang, Ding, 2012, Togeciphus Nishijima and Neoloxotaenia Sabrosky (Diptera: Chloropidae) from China, Zootaxa 3298, pp. 17-29 : 25-28

Neoloxotaenia gracilis (de Meijere, 1908)

(Figs. 23, 24, 26, 34–40)

Lagaroceras gracile de Meijere, 1908: 170. Type locality: INDONESIA: Java.

Loxotaenia gracilis: Becker 1911: 84 ; Frey 1923: 83; Becker 1924: 118; Duda 1930: 297; Duda 1934: 130. Neoloxotaenia gracilis: Sabrosky 1964: 180 ; Sabrosky 1977: 314; Andersson 1977: 168; Kanmiya 1978: 204; Kanmiya 1983: 237.

Diagnosis. Antenna black with thick grayish microtomentum except for postpedicel slightly brown at basoventral portion; postpedicel 3.5 times as long as wide. Paratergite, anepisternum and katepisternum with oblique, wide, white stripe, these parts with distinct pale gray microtomentum. Scutellum entirely black.

Description. Body length 2.4–2.8 mm, wing length 1.8–2.0 mm.

Head black, partly blackish brown, about 0.8 times as long as high, wider than thorax; face somewhat convex in lateral view, bright dark brown; frons dark brown, about 1.4 times as long as wide, projecting only slightly in front of eye. Ocellar triangle smooth, bright black, covering most part of frons; ocellar tubercle bright black; gena narrowed, linear, about 1/10 times as high as postpedicel; vibrissal angle obtuse; parafacial blackish brown, but appearing silvery from a different angle. Cephalic setulae and setae black, weakly developed, except for setulae on parafacial and vibrissal angle pale. orb very minute; oc, pvt and vte hair-like. Antenna longer, black with thick grayish microtomentum except for postpedicel slightly yellowish brown at basoventral portion; postpedicel 3.5 times as long as wide, parallel-sided; arista slender, naked and black except for basal segment yellow. Proboscis light brown with brownish setulae; palpus black with blackish setulae.

Thorax black with brownish microtomentum. Scutum convex, the microtomentum partly sparse or absent and appearing as 5 subshining black stripes, three middle ones long and wide, two lateral ones short and narrow. Thoracic pleuron black except for scutum marked on paratergite, anepisternum and katepisternum with oblique, wide, white stripe, these parts with distinct pale gray microtomentum, katepisternum with some pale microscopic setulae. Scutellum entirely black with pale microtomentum; round marginally and convex on disc, about 1.8 times as wide as long; ap sc short, only half of scutellum. Setulae and setae on thorax black, setae weakly developed. Legs long and thin; coxae, trochanters and femora black, tibiae and tarsi yellow except for fore tarsomeres 3–5, mid and hind tarsomeres 4–5 dark brown. Setulae on legs yellow except for apical portions of tarsi with some brown setulae. Tibial organ absent. Wing ( Fig. 26 ) hyaline, about 2.8 times as long as wide, veins brown. Relative lengths of 2nd: 3rd: 4th costal sections = 4: 3.2: 1; R4+5 and M1+2 nearly parallel or slightly convergent; discal cell narrow and long; crossveins r-m and m-m not approximate, r-m at basal 0.45 of discal cell. Halter pale yellow on knob, brown on stem.

Abdomen black, medially microtomentose and matt, laterally not microtomentose and shiny; venter brown. Setulae on abdomen black.

Male genitalia ( Figs. 34–37 ): Epandrium short tubular, black with long black setulae, widely opened distally and each inner distal margin narrowed and closed to cercus in dorsal view, with 2 narrow band-like sclerites along posterodorsal notch. Surstylus black, pipe-like, basally broad, with short spinous setulae, distally narrowed, attaching to epandrium anteroventrally, and weakly curving inwards on posterior end. Cercus small, linear-oblong. Gonites arranged in a row; postgonite slightly incurved distally and basally, distally pointed and basally gradually narrowed with sensory setulae, about 5 times as long as wide, basally with 2 long sclerites; pregonite shorter and narrower; distiphallus short cylindrical; basal stalk of phallapodeme prolonged basally, broad and incurved in lateral view. Hypandrium narrowed.

Female similar to male. Body length 2.7 mm, wing length 2.0 mm.

Female genitalia ( Figs. 38–40 ): Tergum 9 subtriangular, nearly as long as wide, with 2 long setae; sternum 9 long and semicircular apically with long setae at apical portion. Cercus long, but stout in lateral view with setae on apical portion.

Material examined. CHINA: Yunnan: 5 males, 1 female, Mengla, 8–13. V. 2009, Tingting Zhang.

Distribution. China (Yunnan, Taiwan), Indonesia, Japan, Philippines, Malaya, Thailand, India, Sri Lanka, USA.

Remarks. Kanmiya examined holotypes or syntypes of all known species in Helsinki, Berlin and Amsterdam and compared this species with N. halterata (de Meijere) in Sumatra and N. umbrosa (Frey) in Philippines. The species is rather similar to N. halterata (de Meijere) and N. umbrosa (Frey) , but is separated from these by having the basal segments of the antenna entirely blackish, postpedicel predominantly blackish, and the halter knob cream white or sometimes pale yellow ( Kanmiya 1983).

Figures

FIGURES 25 – 26. wing. 25. Neoloxotaenia fasciata (de Meijere); 26. Neoloxotaenia gracilis (de Meijere).

FIGURES 34 – 37. Neoloxotaenia gracilis (de Meijere), Male. 34. epandrium, posterior view; 35. epandrium, lateral view; 36. hypandrium and phallic complex, ventral view. 37. hypandrium and phallic complex, lateral view.

FIGURES 38 – 40. Neoloxotaenia fasciata (de Meijere), Female. 38. terminalia, dorsal view; 39. terminalia, lateral view; 40. terminalia, ventral view.