Robustagramma triangulatum 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 : 94-95

Robustagramma triangulatum Cui and Marshall , new species

( Figs. 287–293 , 372 )

Body length 1.3–1.8 mm. General color dark brown, lightly pollinose. Abdominal tergites moderately shiny.

Head: Face and antenna brown, gena and lower frons reddish; head otherwise dark brown. Interfrontal bristles in 3 pairs, middle pair very large and cruciate, and other two pairs small. Two orbital bristles, anterior orbital bristle ca. 2/3 as long as posterior. Uppermost orbital setula present between orbital bristles; lower orbital setulae small. Inner and outer vertical bristle, ocellar bristle, and inner and outer occipital bristle well developed; postvertical bristle over half as long as inner occipital bristle; postocellar bristles absent. Eye height ca. 2.1–2.3 times genal height. Arista subequal in length to head height. Aristal hairs long, ca. 4 times as long as basal width of arista. Palpus thin, maximum palpal width ca. 1/6 as long as palpus. Preapical palpal bristles ca. 2.5–3.0 times as long as maximum width of palpus.

Thorax: Acrostichal setulae in 8 rows between anterior postsutural dorsocentral bristles. One or two pairs of setulae between prescutellar acrostichal and dorsocentral bristle. Apical scutellar bristle ca. 1.8 times length of scutellum. Posterodorsal katepisternal bristle strong, over 3/4 as long as distance between bristle base and wing base; anterodorsal katepisternal bristle small. Length of second costal sector ca. 0.40–0.42X length of third. R 2+3 short, distal third slightly curved forward. Costa ending before wing apex, extending past R 4+5 by one vein width. Discal cell without appendices. Tarsi and fore tibia brownish yellow. Mid tibia with a dorsal proximal bristle, a small anterodorsal bristle near middle, and an anterodorsal, dorsal and posterodorsal distally. Mid femur with 4–5 anterior bristles on distal half and a posterodorsal apical bristle. Mid tibia of male with an apicoventral bristle and several ventral setulae on distal third; mid femur of male with one or two irregular rows of 4–6 ventral proximal bristles.

Male abdomen: Abdominal tergites uniformly dark and similar in length. Sternite 5 ca. 1.5 times as long as sternite 4, with two patches of short scales on posteromedial margin. Dorsomedial length of epandrium ca. 0.25X length of sternite 8. Surstylus entirely setose. Cercus short, nearly triangular in shape in posterior view, and setulose at base only. Distiphallus complex, with a pair of dorsal, whip­like, nodose sclerites. Ejaculatory apodeme ca. 1/4 as long as aedeagal apodeme.

Female abdomen: Tergites 1–7 uniformly pigmented and entire. Sternite 7 shorter than sternite 6, rounded posteromedially. Sternite 8 reduced to 2 small sclerites. Sternite 10 transverse, setulose. Spermathecae with elliptical distal portion much larger than conical basal portion. Spermathecal ducts nearly 4 times as long as spermathecal body.

Holotype (♂, DEBU) paratypes (51 ♂, 14 ♀, DEBU): CUBA: Santiago. Gran Piedra Met. Radar, 1100m, elfin forest, dung traps, 6–17.xii.1995, S. Peck.

Other paratypes: Same data as holotype, but carrion traps (7 ♂, DEBU) , FIT (2 ♂, DEBU) , and 7–17.xii.1995, FITs (4 ♂, 5 ♀, DEBU) .

Etymology: The specific epithet triangulatum refers to the shape of the male cercus.

Figures

FIGURES 287–293. Robustagramma triangulatum sp. nov.: 287, posterior view of male terminalia; 288, lateral view of male terminalia; 289, lateral view of male internal genitalia; 290, male sternite 5; 291, dorsal view of female terminalia; 292, ventral view of female terminalia; 293, spermathecae.

FIGURES 371–378. Robustagramma spp. wings (not to scale): 371, R. biangulatum sp. nov.; 372, R.triangulatum sp. nov.; 373, R. brevicauda sp. nov.; 374, R. cultriforme sp. nov.; 375, R. flavistylum sp. nov.; 376, R. disjunctum sp. nov.; 377, R. acutistylum sp. nov.; 378, R. mirabile sp. nov.