Pleurigona bicolor, Li & Qi & Yang, 2020

Li, Wenliang, Qi, Ling & Yang, Ding, 2020, First Chinese record and the second species of the genus Pleurigona Malloch, 1929 (Diptera: Lauxaniidae), Revue suisse de Zoologie 127 (2), pp. 245-248 : 245-248

Pleurigona bicolor sp. nov.

Figs 1-10

Type material: Holotype, male; CHINA, Guizhou Province, Suiyang, Kuankuoshui reserve, Zhongxinzhan , 28.2076 ° N 107.1726 ° E, 1449 m; collected 15.08.2010; collector Guoquan Wang ( CAU) . – Paratypes, 1 male, 1 female; otherwise same data as holotype ( CAU) .

Diagnosis: Head ( Fig. 1 ) pale yellow, with brown lateral band; face slightly convex; frons inclined strongly, face and anterior mesoscutum on same plane. Mesoscutum ( Fig. 4 ) with 1 pair of wide brown lateral bands, 1 wide brown median band composed of 5-6 brown oval spots which get brighter from poasterior to anterior; wing ( Fig. 2 ) with basal third hyaline, with some brown spots at cross points of veins; costal cell R 2+3, R 4+5, M 1 each with 1 square apical spot, except apical spot of R

4+5

nearly flabelliform; a brown spot each on r-m and anterior apex of dm-cu; all brown spots on brownish area surrounded with hyaline margin. Abdomen ( Fig. 5 ) brownish; anterior margin of tergites 1-2 pale yellow.

Etymology: Latin, bicolor , meaning bicolour, referring to wing hyaline basally and brown apically.

Description of male: Body length 3.3-3.5 mm, wing length 4.3-4.5 mm.

Head ( Fig. 1 ): Pale yellow, with brown lateral band, covering frons partly above eye, gena, ventral corner of face, and lateral clypeus below eye. Face slightly convex. Frons yellow, about as long as wide and parallel-sided, inclined strongly, with face and anterior mesoscutum on same plane. Ocellar triangle yellow; oc strong, longer than posterior or, anterior or reclinated and shorter than posterior or. Gena about 1/3 height of eye. Antenna yellowish, 1st flagellomere 1.4 times longer than high; arista short pubescent, brown except yellow base, with longest hairs as long as 1/2 width of 1st flagellomere. Proboscis yellowish with margin black partly, with yellowish and blackish hairs; palpus pale yellow with black hairs.

Thorax ( Fig. 4 ): Yellow with grayish white pruinescence. Mesoscutum with 1 pair of wide brown lateral bands, 1 wide brown median band composed of 5-6 brown oval spots which get brighter from posterior to anterior. Scutellum brown largely except base and lateral margin yellow. Anepimeron with 1 brown spot at ventral corner. Propleuroseta present, 1+3 dc, 1+3 strong acr in 2 rows, 1 pair strong prsc as long as 1st post-sutural dc, 1 ia, 1 anepst, 2 kepst. Legs pale yellow. Fore femur with 6 strong pv, 7 pd and 5 p; fore tibia with 1 long preapical ad and 1 short apv. Mid femur with weak a; mid tibia with 1 short preapical ad and 1 strong apv. Hind tibia with 1 long preapical ad and 2 apv. Wing ( Fig. 2 ) slightly brown, basal third hyaline with some small brown spots at cross points of veins; costal cell, R 2+3, R 4+5, M 1 each with 1 square apical spot, except R 4+5 nearly flabelliform; brown spot each on r-m and anterior apex of dm-cu; all brown spots in brownish area surrounded with hyaline margin; costa with 2nd (between R 1 and R 2+3), 3rd (between R 2+3 and R 4+5) and 4th (between R 4+5 and M 1) sections in proportion of 5.8: 6.5: 4.2; r-m behind middle of discal cell; ultimate and penultimate sections of M 1 in proportion of 5.7: 2.4; ultimate section of CuA 1 about 1/4 of penultimate. Halter pale yellow.

Abdomen ( Fig. 5 ): Brownish, anterior margin of tergites 1-2 pale yellow, syntergosternite circular, with setae near spiracle. Male genitalia ( Figs 6-10 ): epandrium nearly trapezoidal in lateral view; surstylus long with many bristles, tapered apically with incision at preapical anterior margin; hypandrium narrow without distinct hypandrial apodeme; gonopod short with many bristles, and combined with hypandrium; phallus with pair of acute lateral processes but without apical incision; phallapodeme short; ejaculatory apodeme large.

Description of female: Body length 3.3 mm, wing length 4.3 mm. Bands on mesoscutum darker than male; scutellum blackish brown. Abdomen brown; median region of tergite 2 blackish brown.

Distribution: China (Guizhou).

Remarks: This genus resembles somewhat the genus Xangelina Walker, 1856 in the following characters: frons inclined and on the same plane with face and anterior mesoscutum; mesoscutum arched strongly. But it can be separated from the latter by the trait “R 2+3 roundly curved forward at apex”. Pleurigona bicolor also can be separated from Pleurigona curvinervis by the wing pattern.

Figures

Figs 1-5. Pleurigona bicolor sp. nov. Male. (1) Body, lateral view. (2) Wing. (3) Head, dorsal view. (4) Mesoscutum, dorsal view. (5) Abdomen, dorsal view.

Figs 6-10. Pleurigona bicolor sp. nov. Male. (6) Protandrium and epandrium, lateral view. (7) Epandrial complex, posterior view. (8) Protandrium, anterior view. (9) Phallic complex, ventral view. (10) Phallic complex, lateral view. Scale 0.5 mm. e: epandrium; s: surstylus; ea: ejaculatory apodeme; p: phallapodeme; h: hypandrium; g: gonopod.