Grallipeza nigrivitta, Marshall, S. A., 2013

Marshall, S. A., 2013, Grallipeza Rondani (Diptera: Micropezidae: Taeniapterinae) of the Caribbean and North America, Zootaxa 3682 (1), pp. 45-84 : 69-70

Grallipeza nigrivitta new species

Figs. 45–48

Description: Size: Approximately 8 mm. Colour: Head orange except shining reddish brown clypeus and velvet black frontal vitta (black extending to behind ocelli; Fig 47 ). Thorax indistinctly patterned, scutellum and posterior half of scutum dark brown, anterior half yellow-brown except for two narrow longitudinal brown dorsocentral strips; postpronotum brown, pleuron entirely orange. Fore femur black on distal half, tarsomere one and tarsomere two off-white, other tarsomeres brown. Mid and hind femur femora brown on basal half, fading to yellow on distal half, apex very pale. Katepisternal bristles black. Abdominal tergites two and three pale, contrasting with dark tergite one. Female abdominal pleuron apparently unpigmented; oviscape and tergite 6 shining pale brown.

Head: Arista conspicuously long-haired at least over basal half. Pedicel with long ventroapical bristles, one distinctly longer than first flagellomere. Supraantennal shelf small, covered or barely exposed as a triangular piece between lower frons and scape. Lunule with black setulae, face pale setulose. Clypeus shining brown. Palpus tapered apically, with short dark bristles on ventral half and apex. Gena with dense silvery setulae. Frontal vitta broadened and slightly raised in front of ocelli; narrow, parallel-sided and depressed behind ocelli.

Thorax: Cervical sclerite of male smooth with a broad transverse groove; cervical sclerite of female convex ventrally, most of ventral surface densely covered with distinct pores. Prosternum with 5–6 small setulae on each side; mesosternum with a transverse row of 4 long bristles on each side. Fore femur with only small ventral setulae. Two distinct dorsocentral bristles, 5 long exclinate suprahumeral bristles. Postpronotum with only a few minute, indistinct setulae. Wing: Anal cell microsetulose, wing membrane lightly and evenly infuscated over distal ¾ ( Fig. 45 ).

Female abdomen: Oviscape relatively broad and short, just under twice as long as tergite 6 and less than half as long as preabdomen. Common spermathecal duct gradually expanded to a broad apex, paired spermatheca not visible on available dissection (apex of common duct fused with hindgut; Fig. 46 ). Single spermathecae unusually large, broader than apex of common spermathecal duct and comprising a dense, wrinkled mass; single spermathecal duct uniformly narrow, half as long as common duct and twice as long as single spermatheca.

Male abdomen: Sternite 5 narrow, genital fork equal in length to base, inner surface of arms with a single basal tooth, two teeth near middle, and 2–4 clustered near apex; all surfaces sparsely long setose. Epandrium entirely microtrichose and sparsely setulose, 1.5 times as long as wide, slightly longer than the entirely bare and shining sternite 8. The only available males (2 paratypes) were not dissected and the phallus is largely hidden.

Type material: Holotype (female, CMNH 332,741) and four paratypes (2 3, 2 Ƥ, CMHH 329,284; 328,780; 317,840; 331,682): Dominican Republic. Pedernales. Upper Las Abejas. 38kmNNW Cabo Rojo, 18-09N, 78-38W, 1350m, 22.vii.1990, sweeping, L. Masner. Other paratypes: Dominican Republic. RD-266, Las Abejas, P.N. Sierra de Bahoruco, D. Perez (1 Ƥ, USNM).

Comments: This species is part of a species group including Grallipeza albiterga and G. pleuritica , characterized by desclerotization of tergites 2–3, a dark lower vitta, and pigmentation of the scutum. The huge, wrinkled single spermatheca and the gradually widened common spermathecal duct are unlike any other known Grallipeza female.

Etymology: Grallipeza nigrivitta is named for its extensively black frontal vitta.

Figures

FIGURES 45 – 48. Grallipeza nigrivitta. 45, female right lateral; 46, spermathecae and ducts; 47, female head and thorax dorsal; 48, male abdomen ventral.