Grallipeza placidoides (Cresson)

Marshall, S. A., 2013, Grallipeza Rondani (Diptera: Micropezidae: Taeniapterinae) of the Caribbean and North America, Zootaxa 3682 (1), pp. 45-84 : 77

Grallipeza placidoides (Cresson)

Figs. 70–75

Systellapha placidoides Cresson 1926:265

Grallipeza placidoides, Hennig 1934:307 , Steyskal, 1968:48.8.

Description: Size: Approximately 8 mm. Colour: Head, including frontal vitta and palpus, almost entirely orange, only ocellar triangle black; gena and central occiput all or partly silvery. Leg pigmentation sexually dimorphic, female with dorsal part and distal half of fore femur and all of fore tibia black, all fore tarsomeres white; male with fore femur and fore tibia mostly brown and basal fore tarsomere pale brown, darker dorsally. Both sexes with first tarsomere of hind leg white, contrasting with other tarsomeres. Thorax almost entirely orange, sometimes with silvered or browned patches on the pleuron. Abdominal pleuron black along dorsal margin, white on at least ventral ¾. Katepisternal bristles golden.

Head: Arista conspicuously long-haired at least over basal ¾. Pedicel with long ventroapical bristles, one almost as long as first flagellomere. Supraantennal shelf small but exposed between lower frons and scape. Lunule and face with a few small pale setulae. Clypus shining orange. Frontal vitta slightly tapered anteriorly and almost parallel-sided behind ocelli ( Fig. 75 ).

Thorax: Cervical sclerite glabrous, unmodified. Postpronotum microtrichose, but with only a few small setae. One small suprahumeral bristle, at end of a complete row of minute dorsocentral setulae. Fore femur with only small ventral setulae. Two distinct dorsocentral bristles. Wing: Anal cell setulose, wing membrane with an elongate dark central spot widely separated from margins.

Male abdomen: Pleuron of segment 2 with a very large, semispherical membranous dome occupying most of segment, not differing in pigmentation from surrounding pale membrane. Tergite 5 shining black, preabdominal tergites dull brown, epandrium shining brown on basal half, distally setulose; cerci yellow. Epandrium markedly small, similar in size to the genital fork on sternite 5. Genital fork deeply V-shaped at base; apex of each arm with long, dense golden setae; mesal surface with 3 stout teeth spread out along inner surface of lobe. Phallus elongate, phallic bulb compact oval ( Fig. 71 ).

Female abdomen: Tergites 1–5 dull, microtrichose, tergite 6 and oviscape black and shining (apex of oviscape orange). Spermathecae with a pair of large, recumbent and oval spermathecae on a long common duct without conspicuous swelling before splitting into separate stems for the two spermathecae; single spermatheca small and transverse, on a thin duct about half as long as the duct leading to the large spermathecae ( Fig. 72 ).

Type material: Holotype female, CUIC: West Indies, St. Lucia, Castries, September 1919, J.C. Bradley.

Non-type material examined: St. Lucia, Descartiers Trail, and Saltibus trail, 24 and 25.xii.2002, S.A. Marshall (50 specimens); Anse La Raya, Anse Galet, 1km SSW, 50m, 21–30.vi.1991, Rawlins, Thompson (4 Ƥ, 1 3, CMNH); Micoud District Scap Community, 45m, small stream, dry forest, 2.v.2009, J.B. Runyon (1 3, MTEC).

Distribution: Hennig lists a specimen (from the AMNH) of this species from Cuba, but this is likely to be a misidentification of S. placida .

Comments: Cresson described this species from a single female, diagnosing it in part on the “entirely white fore tarsi”. In the same paper he described G. spinuliger from a single male, characterizing it in part by the dark “base of fore tarsi”. Hennig (1934) used this same character to distinguish these species in his key, which would thus key out males and females of G. placidoides to G. spinuliger and G. placidoides , respectively. These two species are endemic to different islands, and differ in other characters as keyed here. Grallipeza placidoides seems to be common in St. Lucia, often abounding in disturbed but forested areas.

Figures

FIGURES 66 – 75. Grallipeza spinuliger (larvae) and G. placidoides (adults). 66, larvae; 67, larva posterior lateral to show spiracular disc; 68, larva anterior lateral, 69, larva spiracular discs; 70, male sternite 5; 71, aedeagus and associated parts; 72, spermathecae and ducts; 73, live female; 74, female right lateral; 75, female head and thorax dorsal. Abbreviations: hy, hypandrium; ph, phallapodeme; pb, phallic bulb.