Allometopon falcistylum Sasakawa, 1964

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 23

Allometopon falcistylum Sasakawa, 1964

Figs 295–297

Allometopon falcistylus Sasakawa 1964: 14 . Soós 1984: 12 [catalogue, Palaearctic]; Sueyoshi 2006: 4 [ Japan].

Description. General: ( Fig. 297 ) Body length 3.9mm. Arista pubescent. M1+2 ratio 3.4. First flagellomere slightly enlarged, more lobate ventrally. Face with medial carina (possibly only shallow and rounded) on dorsal third. Female unknown.

Chaetotaxy: Four fronto-orbital setae, second from back longest, first and third from back slightly shorter, anterior seta slightly shorter than next seta. Ocellar seta appearing slightly longer than ocellar tubercle, twice length of postvertical. Interfrontal seta small but well-developed. First flagellomere along distal margin with hairs longer than width of arista base. Three dorsocentral setae, anterior two approximately half length of third; positioning unknown but likely displaced posteriorly. Acrostichal seta not mentioned in original description. One lateral scutellar seta.

Colour: Setae yellow to brownish-yellow. Head yellow, dorsally with brown tint, ocellar tubercle brown, base of arista yellow. Notum yellow in ground colour; scutum with one pair of narrow brown stripes along dorsocentral rows on anterior half that widen laterally to postpronotum, lateral margin brown from alar base to postpronotum (stripe not reaching ventral 1/3 of postpronotum or notopleural setae), and posterolateral corner of scutum with brown spot on postalar callus; scutellum yellow; metanotum yellow with mediotergite and dorsal corner of anatergite brownish. Legs yellow. Wing clear with pale brown spot on distal 2/5 between costa and vein M. Halter yellow. Abdomen brown with tergite 1 and anterior 2/3 of tergite 2 yellowish; sternites brownish.

Male terminalia: ( Figs 295, 296 ) Epandrium slightly higher than wide. Cercus small, very narrow. Approximate basal third of surstylus well-developed with small, tubercle-like setae along inner-posterior margin; medial third narrow, curved inwards; apical third expanded, apex broad, flat, directed inwards, with small, tubercle-like setae along inner-posterior margin, mostly clustered ventrally. Hypandrium well-developed. Phallapodeme with head atrophied, ventral surface possibly broad and dome-like. Pregonite (not readily distinguished in illustration) small, bare, clavate. Postgonite lobate and setose. Basiphallus short. Epiphallus short, projecting and curved. Distiphallus approximately as long as phallapodeme. Paraphallus half length of distiphallus, tapering apically and with dorsal surface minutely spinulose.

Distribution: Japan.

Holotype: JAPAN. Hokkaido: Kushiro, Nibushi, 19.vii.1953, S. Ito (1♂, KPU). [Not examined]

Comments: The original depository for the holotype of Allometopon flacistylum stated in Sasakawa (1964) was UOPJ, but is now housed at KPU. The specific epithet is corrected here for gender agreement with the genus name.

Figures

FIGURES 291 – 297. 291 – 292. Allometopon atromaculatum (Hennig), holotype; 291: photo, dorsal; 292: same, lateral. 293 – 294. A. bivittatum spec. nov., holotype; 293: photo, dorsal; 294: same, lateral. 295 – 297. A. falcistylum Sasakawa, holotype; 295: external genitalia, posterior; 296: internal genitalia, left lateral; 297: head. Illustrations from Sasakawa (1964).