Robustagramma rarum 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 : 42-43

Robustagramma rarum Cui and Marshall , new species

( Figs. 81–84 )

As described for Robustagramma binitidum except as follows.

Body length 1.7 mm. General color dark brown. Gena and lower frons reddish brown; face and antenna brown. Two orbital bristles, anterior orbital bristle small (most head bristles of unique type damaged or lost). Postvertical bristles similar in size to anterior orbital bristle. Postocellar bristles weak. Eye height ca. 2.6 times genal height.

Acrostichal setulae in 6 or 8 irregular rows between anterior dorsocentral bristles. Posterodorsal katepisternal bristle over half as long as distance between bristle base and wing base. Wing with length ratio of second to third costal sectors ca. 0.56. Discal cell rounded, without appendices. Mid femur of male with two anterior subapical bristles, 7 ventral proximal bristles and one posterodorsal apical bristles.

Male terminalia: Sternite 5 ca. 1.5 times as long as sternite 4, with many dark, clublike scales on posteromedial margin, two patches of short, stout bristles on central area, and a borderline between pale posterocentral area and dark anterior area; without shining patches. Dorsomedial length of epandrium ca. 0.25X length of sternite 8. Surstylus entirely setose; cerci cuneate, shorter than surstylus. Ejaculatory apodeme small.

Holotype (♂, DEBU): VENEZUELA: Bolívar, km 40 Sta. Elena­Icabaru Road, 1000m, 4–6.viii.1986, B. Gill.

Etymology: The specific epithet refers to the apparent rarity of Robustagramma rarum .

Comments: Robustagramma rarum differs from Robustagramma obscuratum Cui and Marshall , new speciesin surstylar setosity and shape. Two male specimens (labelled: COLUMBIA. Leticia, pepper farm, dung, iii.1974, V. Nealis), with terminalia identical to that of Robustagramma rarum probably belong to this species, but they are distinctly smaller in size (1.35 mm), more yellowish in color, and have smaller eyes (2.1–2.3 times genal height).

Figures

FIGURES 81–84. Robustagramma rarum sp. nov.: 81, posterior view of male terminalia; 82, lateral view of male terminalia; 83, lateral view of male internal genitalia; 84, male sternite 5.