Pygophora laoensis Yoshizawa & Tachi

Yoshizawa, Satoshi, Tachi, Takuji, Praxaysonbath, Bounthob & Suzuki, Dai, 2015, A new species of the genus Pygophora Schiner from Laos (Diptera: Muscidae), Zootaxa 3920 (4), pp. 586-592 : 589-592

Pygophora laoensis Yoshizawa & Tachi sp. nov.

( Figs. 2, 4 , 10–14 , 17–18 )

Diagnosis. Fronto-orbital plate yellowish white with 2 frontal and 2 reclinate orbital setae and several setulae; face, parafacial and gena white; first flagellomere cream white, approximately 3.0 times as long as pedicel in male and 2.0–2.2 times in female; third aristomere plumose nearly to apex; fore tibia without anterodorsal seta; mid femur with 2 preapical posterior setae; tergites 3–5 with a median blackish brown vitta; tergite 4 with a pair of blackish brown spots.

Description. Male. Head ( Fig. 2 ). Fronto-orbital plate yellowish white; Face, parafacial and gena white; frontal vitta cream yellow to orange; occiput gray; antenna with scape, pedicel, first flagellomere, first and second aristomeres cream white; third aristomere brown; palpus and labellum whitish yellow; prementum brown. Frontorbital plate with 2 frontal and 2 reclinate orbital setae and several setulae; first flagellomere 2.8–3.0 times as long as pedicel; third aristomere plumose almost up to apex.

Thorax. Dorsum and pleura black in ground color with blackish gray pruinosity; anterior and posterior spiracles yellowish white.

Legs. Fore coxa, trochanters, femora, tibiae, tarsi and pulvilli brownish yellow; mid and hind coxae gray in basal part, brownish yellow apically. Fore tibia with 1 posterior seta; mid femur with 2 preapical posterior setae; mid tibia with 2 posterodorsal setae; hind tibia with 2 anterodorsal, 1 anteroventral and 2 posterodorsal setae.

Abdomen ( Figs. 4 , 12 , 17 ). Yellow in ground color; tergites 3–5 with a median blackish brown vitta; tergites 4 and 5 with a pair of blackish brown spots. Syntergite 1+2 and tergites 3–5 with several pairs of lateral discal setae; tergites 3–5 with 4–6 marginal setae; tergite 5 without a dorsal keel; sternite 5 in ventral view short and broad, bilobed and rounded posteriorly, and with some setae on posterior 3/5.

Male terminalia ( Figs. 10–11, 13 ). Epandrium semicircular with many setae in dorsal view; surstylus in lateral view truncated apically with some setae near middle on anterior margin, in dorsal view short and protruding inward; cerci in lateral view truncated apically with some setae on entire length, in dorsal view nearly oblong and concaved at middle; bacilliform sclerite absent; hypandrial arms fused and strongly broad; pregonite absent; postgonite curved dorsally at basal 2/5, broad on apical half and strongly incised near apex; phallus with distiphallus nearly rectangular bearing large membranous areas at lateral part.

Female ( Fig. 18 ). Differing from male as follows: face, parafacial and gena yellowish white; antenna with scape, pedicel, first flagellomere, first and second aristomeres yellow; syntergite 1+2 with a median blackish brown vitta; tergite 3 with a large median blackish brown spot; tergite 4 blackish brown except anterior and posterior margins; tergite 5 with 3 blackish brown spots; first flagellomere 2.0–2.2 times as long as pedicel. Female terminalia ( Fig. 14 ). Tergite 6 and sternites 7–8 strongly reduced; sternite 6 broad; hemitergite 7 small and bare; hemitergite 8 nearly triangular with some fine setulae on posterior margin.

Body length. 3.4–4.2 mm (males and females, n=4).

Type material examined. Holotype. Male, [ LAOS] Ban Pakbong [N 15°09’21” / E 106°46’35”], 31. VIII. 2013, S. Yoshizawa leg.

Paratypes. One male, same data as holotype; 2 females, LAOS, Houayxay [N 15°23’10” / E 106°22’26”], 2. IX. 2013, same collector.

Distribution. Laos.

Bionomics. This species inhabits in the forest environment.

Etymology. Species epithet is taken from the type locality.

Remarks. This new species is thought to be related to Pygophora argentea Paramonov, P. f l a v i d a Crosskey, P. nitidiventris Malloch and P. orbiculata Cui et Zhang in that they share the following features: third aristomere apically plumose, fronto-orbital plate bearing several setulae, fore tibia lacking anterodorsal seta, and male terminalia possessing short surstylus. Judging from the descriptions and illustrations of the latter four species ( Crosskey, 1962; Cui et al., 1995), P. laoensis may be distinguished from them based on a first flagellomere approximately 3.0 times as long as pedicel in male and 2.0–2.2 times in female, and male terminalia with distiphallus lacking a ventral process at base ( Fig. 13 ).

Figures

FIGURES 1 – 4. Male head and abdomen in lateral view. 1. Male head of Pygophora immaculipennis Frey. 2. Male head of P. laoensis sp. nov. 3. Male abdomen of P. immaculipennis Frey (setae omitted). 4. Male abdomen of P. laoensis sp. nov. (setae omitted). (Scale bars = 0.2 mm). (Abbreviations: comp eye: compound eye; dk: dorsal keel; ped: pedicel; syn 1 + 2: syntergite 1 + 2; T 3: tergite 3; T 4: tergite 4; T 5: tergite 5; thr ari: third aristomere).

FIGURES 10 – 14. Male sternite 5, male and female terminalia of Pygophora laoensis sp. nov.: 10. Epandrium, surstylus and cerci in lateral view. 11. Same in dorsal view (setae omitted on the left side). 12. Male sternite 5 in ventral view (setae omitted on the left side). 13. Hypandrium, postgonite and phallus in lateral view. 14. Female terminalia in lateral view. (Scale bars = 0.2 mm). (Abbreviation: pgt: postgonite).

FIGURES 15 – 18. Male and female adults in dorsal view: 15. Pygophora immaculipennis Frey, male. 16. P. immaculipennis Frey, female. 17. P. laoensis sp. nov., male. 18. P. laoensis sp. nov., female.