Phyllomyza quadratpalpus, Xi, Yu-Qiang, Yang, Ding & Yin, Xin-Ming, 2018

Xi, Yu-Qiang, Yang, Ding & Yin, Xin-Ming, 2018, The genus Phyllomyza Fallen from China, with descriptions of three new species (Diptera, Milichiidae), ZooKeys 760, pp. 143-157 : 143

Phyllomyza quadratpalpus sp. n. Figs 9-12

Diagnosis.

Gena narrowed, approximately one-twelfth of eye height. Surstylus with upper blade of bifurcated tip extremely swollen, lower one slightly swollen and shorter than upper one.

Description.

Male. Body length 1.6-1.8 mm; wing length 1.6-1.8 mm.

Head (Fig. 9) black with grayish microtomentum; orbital plate satiny black, with microtomentum, ocellar triangle brownish without microtomentum; lunule transverse luniform, darkish brown with black margin. Posterior eye margin ventrally diverging from head margin; eye 1.4 times as high as long, gena approximately one-twelfth of eye height. Setae and setulae on head black; ocellar triangle with two ocellar setae and three short setae; frons with three orbital and two frontal setae on brownish orbital stripe, orbital setae lateroclinate and frontal setae medioclinate, four interfrontal setae; postocellar setae converging. Lunule with two short setae. Vibrissal angle flat, the tip almost a 90°angle; vibrissa strong, located at level of lower margin of eye. Antenna brownish brown; pedicel with black setulae at middle and margin, setulae at margin longer than others, longest one 4.5 times longer than others; first flagellomere with pubescence, shallowly oblong and margin blunt; arista 2.5 times as long as first flagellomere, black, distinctly pubescent. Proboscis thick and geniculate, 0.4 mm, brownish, with short sparse black setulae. Palpus flat, irregularly quadrate in lateral view, 2.5 times longer than wide; darkish brown with short dense black pubescence, margin with short sparse setulae.

Thorax darkish brown with grey microtomentum, except scutum shiny blackish brown with sparse black microtomentum; scutellum dark brown with grey microtomentum. Setae and setulae on thorax black; one h, two dc, one prsc, two npl, one prs, one pos, one sa, one ia, one pa, one kepsts (a row of setulae at forward position); scutellum 1.3 times wider than long, with pair of asc and bsc, asc three times longer than bsc. Legs slender, coxae and femora dark brown, tibiae brownish yellow except hind tibia darkish brown, tarsi yellowish. Setae and setulae on legs black. Mid tibia with a black preapical dorsal seta. Wing (Fig. 10) hyaline, unspotted; veins brown; Sc strong; M1 between r-m and dm-cu a little longer than dm-cu. Calypter yellowish, with brownish microtrichae, margin with brownish setulae. Knob of halter yellowish white, stalk yellowish.

Abdomen brown with grey microtomentum. Setae and setulae on abdomen black; TII-TV with setae at posterior 3/4, marginal setae longer than others; sternites with sparse setulae. Posteromedial triangular projection of TI into TII present; SII generally luniform, SIII oblong, apical margin blunt and round, SIV very broadly obpanduriform, SV shallowly oblong. Male genitalia (Figs 11-12): epandrium with five strong black setae; surstylus with upper blade of bifurcated tip extremely swollen, lower one slightly swollen and shorter than upper one; cercus irregularly arched with short sparse setae.

Female. Body length 1.8-2.0 mm; wing length 1.8-2.0 mm.

Similar to male, but palpus shorter, approximately four-fifths of males’. Female terminalia: TVIII brown, shallowly oblong, margin with setulae. Supra-anal plate broadly trullate; SVIII very shallowly luniform, subanal plate wide, brownish, very depressed trullate. Cercus with long setulae.

Material examined.

Holotype, ♂, China, Guizhou, Libo County, Maolan National Nature Reserve (25°15'36.67"N, 108°03'21.65"E; 620m), 13. X. 2013, Ding Yang (CAU). Paratypes, 5 ♂♂, same data as holotype; 2 ♀♀, China, Guizhou, Libo County, Maolan National Nature Reserve (25°12'32.50"N, 108°21'20.08"E; 830m), 18. VIII. 2017, Xiaohui Hou (HAU).

Distribution.

China (Guizhou).

Etymology.

The specific name refers to the shaped of palpus.

Remarks.

This new species is somewhat similar to P. planipalpis Xi & Yang, but differs in the palpus irregularly quadrate in lateral view, surstylus with upper blade of bifurcated tip extremely swollen and apical margin smooth; in P. planipalpis , the palpus depressed semiluniform in lateral view, surstylus with upper blade of bifurcated tip swollen and apical margin blunt ( Xi and Yang 2015a).