Cyamops crosbyi Mathis and Sueyoshi

Mathis, Wayne N. & Sueyoshi, Masahiro, 2011, New species of the genus Cyamops Melander from New Zealand (Diptera, Periscelididae, Stenomicrinae), ZooKeys 114, pp. 29-40 : 36-38

Cyamops crosbyi Mathis and Sueyoshi sp. n. Figs 5-12

Description.

Adult body length 2.20-2.55 mm; wing length 2.30-2.75 mm; wing width 0.85-1.00 mm.

Head (Fig. 5): Ocellar tubercle sparsely microtomentose, subshiny; shiny spot immediately anterior of lateral vertical seta small, about the size of an ocellus; depressed region of frons densely microtomentose, appearing velvety black; fronto-orbits microtomentose, silvery white. Antenna bicolored, dorsal portion brownish black to black, ventral portion yellow; basal aristal rays minutely bifurcate apically; basal flagellomere yellow, infuscate dorsally. Face constricted medially by the anteroventral margin of the eyes, expanding into a triangular region ventrally below the level of the pseudovibrissae and bearing a verticomedial ridge facial region, face yellow in ground color, strongly microtomentose; labellum and palpus pale yellow; face produced and slightly angulate. Chaetotaxy: Inner fronto-orbital setae slightly divergent, slightly smaller than outer vertical seta; arista bearing 9 dorsal, 3 ventral rays, 6 basal rays bifurcate; pseudovibrissae oriented dorsally; peristomal setae 7.

Thorax: Halter brown; scutellum trapezoidal, orientation of scutellum moderately more elevated than scutum, disk a little convex; postpronotum polished. Chaetotaxy: Dorsocentral setae 0+2, anterior seta greatly reduced in length, at most 1/8 length of posterior seta; mesonotal setulae moderately well-developed; scutellar setae 2, basal seta 1/3 length of apical seta. Wing: Hyaline, slightly fuscous; cells bm and dm separated; 1st costal ratio 2.7-3.0; 2nd costal ratio 2.1-2.4; wing ratio 0.35-0.37; crossvein bm-cu present. Legs mostly yellow; femora mostly yellow, gradually becoming blackish on apical 1/3; tibiae yellowish, blackish basally and especially apically; apical and subapical tarsomere of each leg blackish brown, 3rd tarsomere brown, basal 2 yellowish.

Male abdomen (Figs 6-12): 6th tergite about same width as dorsal portion of 7th tergite, both sclerites almost without setae; 4th and 5th sternites with well-developed lateral setae and a row of setae along posterior margin; 5th sternite twice as wide as long; 6th and 7th sternite asymmetrically bilobed, left lobe much larger than medial lobe. Male terminalia (Figs 7-12): right surstylus with extended portion irregularly angulate, in posterior view (Fig. 7) subtriangular, with obtuse angles, basal stem parallel sided basally; left surstylus (Figs 7-9) moderately broad basally, apical half narrow, ventromedial extension, somewhat digitiform, apex pointed, in lateral view elongate (Fig. 9), almost parallel sided, truncate apically; hypandrium and gonites in ventral as in Fig. 10; aedeagus complex, as in Figs 11-12.

Female: Head: Ventral midfacial triangle black with sparse silvery white microtomentum; gena densely microtomentose, silver except on facial carina where microtomentum is thin; basal flagellomere infuscate dorsally.

Thorax: Legs with femora and tibiae mostly brown.

Abdomen: 7th tergite and sternite separate; 7th tergite about 3/4 length of 6th tergite; 2 subequal, spherical spermathecae; sclerotized portion of spermathecal duct about 1/5 length of spermatheca.

Type material.

The holotype male is labeled "NEW ZEALAND.N.Isl. AK: Cascade (36°53.2'S, 174°31.2'E; 60 m), 2 Jan 2994[,] Wayne N. Mathis/HOLOTYPE ♂ Cyamops crosbyi Mathis & Sueyoshi NZAC [red]." The holotype is double mounted (minuten in a block of plastic), is in excellent condition, and is deposited in the NZAC. Twenty-four paratypes (23♂, 1♀; NZAC, USNM) bear the same locality label data as the holotype.

Other material examined.

NEW ZEALAND. AK: Henderson Valley, Scenic Reserve (36°53.8'S, 174°35.7'E; Candia Road entrance. On plants by stream), 14 Jan 2007, S. E. Thorpe (1♀; NZAC).

Etymology.

The species epithet, crosbyi, is a genitive Latin patronym to honor and recognize the numerous contributions of Dr. Trevor K. Crosby to the study of Diptera from New Zealand, the family Simuliidae in particular.