Pygophora boninensis Snyder, 1965

Yoshizawa, Satoshi & Tachi, Takuji, 2018, Taxonomic review of the genus Pygophora Schiner of Japan (Diptera: Muscidae), Zootaxa 4418 (5), pp. 449-468 : 451-454

Pygophora boninensis Snyder, 1965

( Figs. 1a–e , 2a–d , 11a , 12 )

Pygophora boninensis Snyder, 1965: 230 . Holotype male (United States National Museum, Washington, United States America). Type locality: Omura, Chichijima Is., Japan.

Type material examined. Paratypes: JAPAN: 3 males and 1 female ( BPBM), Camp beach, Omura , Chichijima Is., Ogasawara Iss., Tokyo., 5. V.–9. VI. 1958, F. M. Snyder; 1 male ( BPBM), Okumura, Yankee town , Chichijima Is., Ogasawara Iss., Tokyo, 8–15. IV. 1958, F. M. Snyder ; 1 female ( BPBM), same locality and collector to the preceding data, 12. V.–9. VI. 1958 .

Diagnosis. Male. First flagellomere 3.8–4.0 times as long as pedicel; wing with brown spot on tip of R2+3; hind tibia with 1 posteroventral seta, short and slender apical lobe; abdominal sternite 5 slender and bifurcated posteriorly, with membranous area at middle, short projections at inside and many short setae on posterior 2/ 5 in ventral view; surstylus broad, round apically in lateral view, slender with many setae in dorsal view.

Redescription. Male. Head. Fronto-orbital plate, frontal vitta, face, parafacial yellowish white; gena and occiput gray. Antenna creamy yellow except 3rd aristomere brown; palpus and labella creamy; prementum dark or reddish brown. Vertex approximately 1/4 of head width; frons above lunule approximately 1/3 of head width; parafacial very narrow in the middle, approximately 1/21 of head width; gena narrow, approximately 1/11 of head height; ocellar triangle small, not reaching lunule; 2 frontal setae; 2 reclinate orbital setae; fronto-orbital plate without any supplemental setula; 2 supravibrissal setae; 1 vibrissa; 1–2 subvibrissal setulae; 1 genal seta; compound eye bare. First flagellomere 3.8–4.0 times as long as pedicel; 1 st aristomere as long as wide; 2nd aristomere longer than wide; 3rd aristomere thickened on basal 1/5; arista plumose only on basal half.

Thorax. Scutum, postpronotum, scutellum, and pleura black in ground color, with gray pruinosity; anterior and posterior spiracles creamy. Two proepisternal setae, anterior one shorter than posterior one; 2–3 proepimeral setae; 2 postpronotal setae; acrostichal seta fine; 1 presutural and 3 postsutural dorsocentral setae; 1 presutural and 2 postsutural intra-alar setae; 1 presutural and 1 postsutural supra-alar setae; 2 postalar setae; 2 notopleural setae; 5–6 anepisternal setae; 3 katepisternal setae, forming equilateral triangle; anepimeron, katepimeron, meron, katatergite, and anatergite bare; apical scutellar seta as long as basal one; prosternum bare.

Wing. Brownish hyaline with brown spot on tip of R2+3; tegula, basicosta, and all veins brown; upper and lower calypters white; halter creamy. Vein M not bending anteriorly at apical part; distance of M between crossveins r-m and dm-cu shorter than distance between crossvein dm-cu and wing margin; crossvein dm-cu nearly straight, longer than ultimate section of vein CuA1.

Legs. Fore coxa, all trochanters, femora, tibiae, tarsi, and pulvilli creamy yellow; mid and hind coxae gray in basal part, creamy yellow apically; all claws brown. Fore tibia with 2–4 anterodorsal, 1 posterior, 2 preapical dorsal, and 3 apical ventral setae; mid femur with 2 preapical posterior setae; mid tibia with 2 posterodorsal, 2 preapical dorsal, and 3 apical ventral setae; hind tibia with 2 anterodorsal, 1 anteroventral, 2 posterodorsal, 1 posteroventral, 2 preapical dorsal, 3 apical ventral setae, short and slender apical lobe; pulvillus rectangular in shape.

Abdomen. Creamy yellow in ground color with gray pruinosity at middle; tergite 4 with three black spots. Tergites 3 and 4 with several discal and marginal setae; tergite 5 with several discal, marginal setae, and dorsal keel; sternite 5 slender and bifurcated posteriorly, with membranous area at middle, short projections at inside and many short setae on posterior 2/ 5 in ventral view.

Male terminalia. Tergite 6 very slender; syntergosternite 7+8 small with several setae; sternite 6 slender and symmetric; epandrium nearly semicircular and notched laterally with many setae; surstylus fused with epandrium, broad, round apically in lateral view, slender with many setae in dorsal view; cerci fused with epandrium, bifurcated apically with several setae in dorsal view; hypandrium broad and nearly semicircular; pregonite very small and round apically; postgonite broad and curved dorsally at middle, hook-like apically; phallus curved dorsally, broad, and hook-like with large membranous areas laterally at apical part.

Female. Differing from male as follows: first flagellomere shorter than in male, 2.5–2.7 times as long as pedicel; wing hyaline without brown spot; hind tibia without posteroventral seta and apical lobe; abdominal tergite 3 with three black spots; abdominal tergite 5 without dorsal keel.

Female terminalia. Tergite 6, sternites 7 and 8 strongly reduced with some setulae; sternite 6 broad with setae; hemitergite 7 small and bare; hemitergite 8 narrow with some setulae on posterior margin.

Body length. 6.1–7.0 mm.

Additional material examined. OGASAWARA ISLANDS: 4 males and 1 female (EUM), Mt. Mikazuki, Chichijima Is., 25–26. V. 1973; 1 female (EUM), Kita-fukurozawa, Chichijima Is., 26. V. 1973; 1 male and 1 female (EUM), Camp beach, Omura, Chichijima Is., 5. V.–9. VI. 1958.

Distribution. Japan (Ogasawara Iss.: Chichijima Is.).

Bionomics. Unknown.

Remarks. This species resembles Pygophora macularis (Wiedemann) and P. maculipennis Stein , but it is distinguished from them by having 1 posteroventral seta on hind tibia and slender surstylus in dorsal view in male. However, females of P. boninensis are not able to identify without locality data.

Figures

FIGURE 1. Male and female adults of Pygophora species. P. boninensis Snyder: a, b. Habitus in lateral view (a. Male, b. Female). c, d. Wings in ventral view (c. Male, d. Female). e. Apical part of male hind tibia in anterior view. P. lepidofera (Stein): f. Male abdomen in dorsal view (arrow indicates leaf-like seta) (Scale bars = 2.0 mm in a–b; 1.0 mm in c–d, f; 0.2 mm in e).

FIGURE 2. Pygophora boninensis Snyder, male sternite 5 and terminalia: a. Male sternite 5 in ventral view (setae omitted on the left side). b. Hypandrium, pregonite, postgonite, and phallus in lateral view. c. Epandrium, surstylus, and cerci in lateral view. d. Same in dorsal view (setae omitted on the left side) (Scale bars = 0.2 mm) (Abbreviations. bcs: bacilliform sclerite; cerc:cerci; epand: epandrium; hypand:hypandrium; pgt:postgonite; ph: phallus; prgt:pregonite; sur:surstylus).

FIGURE 11. Female terminalia of species of Pygophora in lateral view: a. P. boninensis Snyder. b. P. longicornis (Stein) (Scale bars = 0.2 mm).

FIGURE 12. Distribution map for Pygophora spp. in Japan:P.boninensis Snyder (black star); P.confusa Stein (white star); P. immaculipennis Frey (black circle); P. lepidofera (Stein) (white circle); P. longicornis (Stein) (black triangle); P. macularis (Wiedemann) (white triangle); P. maculipennis Stein (black square); P. respondens (Walker) (white square); P.unicolor (Stein) (black hexagon).