Parerigone laxifrons, Wang, Qiang, Zhang, Chuntian & Wang, Xinhua, 2015

Wang, Qiang, Zhang, Chuntian & Wang, Xinhua, 2015, Review of the genus Parerigone Brauer (Diptera: Tachinidae) with five new species from China, Zootaxa 3919 (3), pp. 457-478 : 468-470

Parerigone laxifrons sp. nov.

( Figs. 13–16 , 33–36 , 44 )

Diagnosis. Medium-sized black flies, mostly covered with dense yellow pruinosity. Vertex 0.27–0.28 of head width; gena 0.40–0.44 of eye height; 1 strong reclinate orbital seta; all thoracic hairs black, fine short and suberect; scutellum with 1 pair of rather fine long discal seta; all leg hairs black; mid tibia with 1 ventral seta in female and absent in male.

Description. Body length: 9.5–10 mm.

Male. Head black in ground color, reddish on parafacial obliquely from upper anterior margin to lower eye margin and gena, fronto-orbital plate brown to black, frontal vitta reddish brown to black, genal dilation reddish brown, lower face pale yellowish, fronto-orbital plate, parafacial, face, gena and genal dilation covered with grayish white pruinosity, occiput with pale yellow or yellowish white hairs and one or two rows of short black hairs behind postocular seta, covered with yellowish white pruinosity; antenna brown-black; palpus black. Vertex 0.27–0.28 of head width; frontal vitta 0.8–0.9 times as wide as fronto-orbital plate at middle; parafacial 1.1–1.2 times as wide as 1st flagellomere at middle height; face weakly concave, lower margin strongly protruded forward, extending beyond base of vibrissa by 1.0–1.1 times length of pedicel; gena 0.40–0.44 of eye height. Inner vertical seta long, 0.85–0.88 of eye height; outer vertical seta fine, 0.5–0.55 times as long as inner vertical seta; ocellar seta strong, 0.50–0.52 times as long as inner vertical seta and with several fine black hairs on ocellar triangle; 2 postocellar setae, 0.40–0.45 times of inner vertical seta height; 2 posterior vertical setae, 0.45–0.50 times of inner vertical seta height; 9–10 long frontal setae, lowest seta nearly level with basal of pedicel; fronto-orbital plate with only several fine short black hairs among and beyond the row of frontal setae; 1 strong reclinate orbital seta, about 0.55 times as long as inner vertical seta; vibrissa inserted slightly above level of lower margin of face; facial ridge with 3–4 setae and several fine short hairs at most on its lower 2/5; 4–6 rather long subvibrissal setae. Antenna falling short of lower margin of face by about 1.7 times of pedicel length; pedicel bearing black hairs and a long seta, the latter 2.4–2.5 times as long as pedicel; 1st flagellomere about 3.0 times as long pedicel; arista with micropubescence, 3rd aristomere thickened on basal 2/7.

Thorax black in ground color, with dense yellow pruinosity; dorsum with 4 narrow longitudinal vittae, outer vittae about 2 times as wide as inner vittae and about 0.4 times as wide as pruinose portion between inner and outer vittae; pleura with thin grayish white pruinosity. All thoracic hairs black, fine short and suberect; anatergite with fine hairs; 3 presutural and 3 postsutural dorsocentral setae, 3 postsutural supra-alar setae, sometimes with 1 fine long hair inserted between 1st and 2nd postsutural supra-alar setae, anterior seta shorter; scutellum with 3 pairs of marginal setae and 1 pair of rather fine long discal setae, the latter about 1.6 times as long as scutellum, basal and subapical setae subequal in length and about 2.4 times as long as scutellum, apical seta slightly shorter than basal and subapical setae and about 2.0 times as long as scutellum, sometimes 1 rather fine long hair inserted before basal seta.

Wing hyaline, weakly tinged with pale yellow on basal and anterior margins; basicosta reddish brown; lower calypter yellowish white on middle and pale yellow on margin. Costa between subcosta and vein R1 about 0.33 times as long as that between R1 and R2+3; bend of vein M slightly obtuse angled, vein M from dm-cu crossvein to its bend 1.45–1.50 times as long as distance between the bend and wing margin extending along vein M.

Legs black, claws reddish brown, pulvilli pale yellowish brown. All leg hairs black; fore tibia with 2–3 very fine anterodorsal and 2 fine and long posterior setae; mid tibia with 1–2 anterodorsal and 3 posterodorsal setae, if 2 anterodorsal setae present then upper seta fine; hind tibia with a sparsely set row of short and fine anterodorsal setae, 2–3 strong submedian setae among them, if 3 anterodorsal setae present then upper seta fine, 2 posterodorsal setae and 2 strong anteroventral setae, and with 2 preapical dorsal setae.

Abdomen long ovate, black in ground color, entirely covered with dense golden yellow pruinosity, irregular spots appearing with direction of light on dorsum of syntergite 1+2 to 5th tergite. Hairs on dorsum black, fine and short; syntergite 1+2 excaveted half way to posterior margin, with 2 median marginal and 2–3 lateral marginal setae; 3rd tergite with 2 strong median discal, 2 strong median marginal and 3–4 lateral marginal setae; 4th tergite with 2 strong median discal and a row of 10–12 strong marginal setae; 5th tergite with 2 rows of median discal and a row of marginal setae.

Male terminalia. Fifth sternite ( Fig. 35 ) deeply Ω-shaped in ventral view, broadly excavated posteromedially, without membranous area anterior to the excavation, with fine long hairs on posterior lobe; cerci ( Fig. 33 ) narrow sword-like in dorsal view, narrowly separated on basal 1/6 to apex, lateral margin expanded on basal 1/3 to apex, with dense fine short hairs from basal 1/3 to apex and dense strong hairs on basal 1/5, in lateral view dorsal margin nearly straight and ventral margin excavated near middle, bulged on basal 1/3, dorsal area of basal 1/5 concave, apex inwardly concave; surstylus ( Fig. 34 ) broad and long, with dense long fine hairs on lateral margin, obtuse apically; bacilliform sclerite short; pregonite curved posteriorly near middle; postgonite overlapping pregonite on basal 1/2; distiphallus elongate, distal area broadly expanded laterally; ejaculatory apodeme long, nearly fanshaped ( Fig. 36 ).

Female. Differing from male as follows: Palpus reddish yellow, darkened on basal 1/6; vertex wider, about 0.3 of head width; frontal vitta 0.8 of width of fronto-orbital plate at middle; outer vertical seta developed, about 0.65 times as long as inner seta; 1 strong reclinate orbital seta about 0.84 times as long as inner vertical seta, 1 proclinate orbital setae, about 0.65 times as long as inner vertical seta; 7 rather strong frontal setae; ocellar seta hair-like; 1st flagellomere about 3.4 times as long pedicel; mid tibia with 1–2 strong ventral setae, if 2 setae present then the upper one rather short; claws and pulvilli shorter than 5th tarsomere. Female terminalia ( Fig. 44 ). Sixth tergite long and broad; 6th sternite short, flat posteriorly; 7th tergite long and broad; 7th sternite long, divided into two rounded lobes and weakly curved dorsally on posterior portion; 8th tergite long, concave posteriorly; 8th sternite long and strongly sclerotized, strongly curved ventrally in anterior portion, posterior portion forming a piercer.

Holotype male, Qiuqianjia Forestry Centre, Jingyuan, 1800 m, Ningxia, China, 4.vii.2008, J.Y. Liu (SYNU).

Paratype. CHINA: 1 female, Guamagou Forestry Centre, Longyang, 2200 m, Ningxia, 5.vii.2008, Z.Y. Yao (SYNU).

Etymology. Specific name is taken from the wide vertex of this species.

Remarks. Parerigone laxifrons is one of three species in the genus with 3 pairs of scutellar marginal setae, 3 postsutural acrostichal setae and the vertex about 1/5 of head width, the other species being P. takanoi and P. wangi . Within these three species, P. laxifrons and P. takanoi have discal scutellar setae. Parerigone laxifrons differs from P. takanoi in having a wider vertex, palpus black, and male with 1 strong reclinate orbital seta.

Distribution. China (Ningxia).

Figures

FIGURES 13 – 16. Parerigone laxifrons sp. nov., male. 13. Body in dorsal view. 14. Body in lateral view. 15. Head in lateral view. 16. Head in anterior view.

FIGURES 33 – 36. Male terminalia of Parerigone laxifrons sp. nov. 33 – 34. Epandrium, cerci and surstyli. 33. Caudal view. 34. Lateral view. 35. Sternite 5 in ventral view. 36. Aedeagal apodeme, ejaculatory apodeme, hypandrium, pregonite, postgonite, basiphallus, distiphallus in lateral view. Scale bars = 0. 25 mm.

FIGURES 41 – 44. Female terminalia in lateral view. 41. Parerigone atrisetosa sp. nov. 42. Parerigone flava sp. nov. 43. Parerigone flavisquama sp. nov. 44. Parerigone laxifrons sp. nov. Scale bars = 0. 25 mm.