Grallipeza turba Marshall, 2013, new species

Grallipeza turba new species

Figs. 88–93

Description: Size: Approximately 7 mm. Colour: Head, including clypeus, frontal vitta and palpus, almost entirely orange with only ocellar triangle black; anterior part of vitta darkened, corresponding lower parts of orbital strips yellow; gena and central occiput all or partly silvery. Distal quarter or less of fore femur and all of fore tibia black, first fore tarsomere almost all white, apex of first tarsomere and distal four tarsomeres brown. Hind femur pale with a dark apex. Thorax almost entirely orange, except for distinct silvered patch covering dorsal half of katepisternum. Katepisternum with a double row of golden bristles, anterior row small. Abdominal pleuron white, without dark areas in female but crossed by diagonal black stripe in male.

Head: Arista with medium-length hairs (slightly longer than basal aristomere width) over basal half, with short hairs up to ¾. Pedicel with long ventroapical bristles, one as long as first flagellomere. Supraantennal shelf small, barely exposed between lower frons and scape. Lunule and dorsal half of face setulose with dark setulae above and pale setulae below. Frontal vitta slightly expanded anteriorly and parallel-sided from fronto-orbital bristles to back (Fig. 91).

Thorax: Cervical sclerite in male glabrous, ventral surface convex with a weak transverse suture; cervical sclerite of female with most of ventral surface flat, pale and dull but without distinct pits or pores. Postpronotum with small, sparse black bristles. Fore femur with only small ventral setulae. Two distinct dorsocentral bristles, 1 very small suprahumeral bristle and a row of small acrostichal bristles on each side. Wing: Anal cell setulose, membrane with central infuscation diffuse, distal part barely extending across R4+5. Apex of wing indistinctly infuscated (Figs 88, 89).

Male abdomen: Pleuron of segment 2 with a very large, elongate oval membranous dome occupying most of segment, pigmentation much darker than surrounding membrane; pleuron otherwise mostly pale. Genital fork (sternite 5) with about 12 dark teeth on mesal surface, those on basal part widely spaced, those in distal quarter densely packed (Fig. 93). Distiphallus as long as the epandrium with its long anteroventral epandrial arm, ending in a complex internally coiled phallic bulb (Fig. 92).

Female abdomen: Pleuron pale. Tergite one pale, posterior tergites dark, tergites 2–5 dull, tergite 6 shining. Paired spermathecae large, recumbent and U-shaped on a long common duct with distal half very strongly swollen before splitting into separate stems for the two spermathecae; single spermatheca small and T-shaped, on a very slightly swollen duct about 4/5 as long as the duct leading to the larger paired spermathecae (Fig. 90).

Type material: Holotype female (USNM): Dominica, Clarke Hall Est., 19.iv.1966, R. Gagne, Bredin- Archbold Smithsonian Bio. Surv. Dominica.

Paratypes. Dominica. Pont Casse, 23.iii.1989, A. Freidberg (1 3, USNM); Fond Figues R., 400’. 12.iv and 29.v. 1966, R. Gagne (2 Ƥ, USNM); Fond Figues R., rain forest, 3.ii.1965 W.W. Wirth (1 Ƥ, USNM).

Comments: The contrasting dark lower vitta and flanking yellow lower orbits are distinctive, as is the apically dark hind femur and the diffuse central wing infuscation.

Etymology: The specific epithet is from the Greek turba, for “tumult or disorder”, referring to the consternation caused when these specimens turned up amongst a large series of the common Dominican species G. spinuliger. Grallipeza turba appears to be most closely related to G. baracoa and G. nebulosa.