Robustagramma robustinervus Cui and Marshall, 2005

Marshall, Stephen A. & Cui, Yongsheng, 2005, Systematics of Robustagramma, a new genus of New World Sphaeroceridae (Diptera), Zootaxa 1026 (1), pp. 1-122 : 32-34

Robustagramma robustinervus Cui and Marshall , new species

( Figs. 49–55 , 366 )

Body length 1.1–1.3 mm, general color yellowish to brown, moderately pollinose, without conspicuous patterns.

Head: Face, gena, antenna and lower frons yellowish brown to dark brown. Ocellar triangle, interfrontal and orbital strips silvery. Interfrontal bristles in three pairs. Uppermost orbital setula present between orbital bristles, lower orbital setulae smaller. Postvertical bristles distinctly shorter than inner occipital bristle, parallel. Eye height ca. 1.8–2.2 times genal height. Preapical palpal bristles (in male) shorter than, or (in female) subequal to, maximum width of palpus.

Thorax: Prosternum narrow, bare. Acrostichal setulae in 6 irregular rows between anterior dorsocentral bristles; one pair of setulae between prescutellar acrostichal and dorsocentral bristles. Apical scutellar bristles ca. 1.5 times length of scutellum. Posterodorsal katepisternal bristle nearly half as long as distance between bristle base and wing base; anterodorsal bristle very small. Halter knob brown; stem pale yellow. Wing almost clear, half as broad as long; length of second costal sector ca. 0.40–0.42X length of third. Wing of male with first costal sector conspicuously thickened, its width ca. 1.5 times as long as width of second costal sector; wing of female with first costal sector similar in width to second costal sector. R 2+3 straight, or distally slightly curved forward. R 4+5 and costa ending together before wing apex. Discal cell without appendices or with only trace of stump vein CuA 1. Tarsi and fore tibiae yellow to brownish. Mid femur with an anterior preapical bristle. Mid tibia of male with an apicoventral and several short ventral bristles on distal third. Mid femur of male with 3 ventral proximal bristles.

Male abdomen: Sternite 5 over 2.5 times as long as sternite 4, with a pair of finely setulose posterior processes and a large pale central area. Dorsomedial length of epandrium ca. 0.33X length of sternite 8. Distiphallus with a pair of dorsal whip­like sclerites and a pair of large, dark, ventral sclerites. Postgonite with a straight distal half. Ejaculatory apodeme small.

Female abdomen: Tergite 1–7 uniformly pigmented and entire. Sternite 8 incompletely divided into two sclerites; sternite 10 transverse, setulose. Spermathecae ovate, with the apical portions much larger than the basal portions.

Holotype (♂, DEBU) and paratypes (1 ♂, 5 ♀, DEBU): VENEZUELA: Bolívar. Km 40 Santa Elena, Icabaru Road , 1000m, 4–6.viii.1986, B. Gill.

Other paratypes: Same data as holotype, but 100m (1 ♂, DEBU) , 220m (1 ♀, DEBU) . GUYANA: Mazaruni­Potaro Dist , Tukeit Falls, Potaro R., 300', primary rainforest, human dung trap, 27–29.ix.1990, B. Hubley (1 ♂, DEBU) .

Etymology: The specific epithet refers to the thickened first costal sector of the male wing.

Figures

FIGURES 49–55. Robustagramma robustinervus sp. nov.: 49, posterior view of male terminalia; 50, lateral view of male terminalia; 51, lateral view of male internal genitalia; 52, male sternite 5; 53, dorsal view of female terminalia; 54, ventral view of female terminalia; 55, spermathecae.

FIGURES 363–370. Robustagramma spp. wings (not to scale): 363, R. atratum sp. nov.; 364, R. lingulatum sp. nov.; 365, R. setilamella sp. nov.; 366, R. robustinervus sp. nov.; 367, R. binitidum sp. nov.; 368, R. macrosternum sp. nov.; 369, R. longistylum sp. nov.; 370, R. hebes sp. nov.