Grallipeza spinuliger (Cresson)

Marshall, S. A., 2013, Grallipeza Rondani (Diptera: Micropezidae: Taeniapterinae) of the Caribbean and North America, Zootaxa 3682 (1), pp. 45-84 : 80

Grallipeza spinuliger (Cresson)

Figs. 82–87 (adults) and 66–69 (larvae)

Systellapha spinuliger Cresson, 1926: 267 .

Grallipeza spinluliger, Hennig 1934: 307 ; Steyskal 1968: 48.8.

Description: Size: Approximately 8 mm. Colour: Head, including frontal vitta, clypeus, antenna and palpus, almost entirely orange, only ocellar triangle black; gena 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 first fore tarsomere pale brown, darker dorsally. Mid and hind femora uniformly brown. Both sexes with first tarsomere of hind leg white, contrasting with other tarsomeres. Katepisternal bristles golden. Thorax almost entirely orange, sometimes with silvered or browned patches on the pleuron. Abdominal pleuron darkened along dorsal margin, white to cream yellow on at least ventral ¾ ( Fig. 84 ). Male pleuron sometimes darkened around the prominent white pleural dome.

Head: Arista conspicuously long-haired at least over basal 4/5. Pedicel with long golden 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 setulae. Frontal vitta slightly swollen anteriorly then narrowed and depressed near anterior margin, slightly tapered and depressed behind ocelli ( Fig. 83 ).

Thorax: Cervical sclerite convex and smooth in both sexes, sometimes with a weak transverse furrow. Postpronotum with few, indistinct small setulae. Fore femur with only small ventral setulae. Two distinct dorsocentral bristles. Two suprahumeral setae, anterior one distinct and posterior one minute. Wing: Anal cell setulose, wing membrane almost uniformly indistinctly infuscate, slightly darker at tip.

Male abdomen: Preabdominal tergites dull brown, tergite 5 pale brown and sparsely setose, tergite 6 shining bare brown-black, epandrium shining brown and mostly bare except for sparse setae, posterodorsal patch densely setulose; cercus yellow. Epandrium small, slightly shorter than sternite 6, similar in size to the genital fork. Genital fork white, with long, sparse golden apical and lateral setae; mesal surface with 3–4 stout teeth, one near base, one near middle and 1–2 near apex of lobe ( Fig. 86 ). Distiphallus approximately twice as long as epandrium, ending in a dense phallic bulb ( Figs. 85, 87 ).

Female abdomen: Tergite 1 pale, 2–5 dull black-brown, microtrichose, tergite 6 and oviscape brown and shining (apex of oviscape orange). Paired spermathecae large, recumbent and oval 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 slightly shorter than the duct leading to the large spermathecae ( Fig. 82 ).

Larva: Anterior spiracular lobe with a broad, distinct base with about 20 small, closely spaced branches. Posterior spiracular disk with a prominent, pointed dorsolateral process on outer rim and with a deep notch on inner rim; surface with multiple small pores. Ventral creeping welts inconspicuous, in double or triple rows. Mandibles short, strongly bent; remainder of cephalopharyngeal skeleton weakly sclerotized.

Type material: Holotype (male, USN327069) Dominica, vi–vii.1913, H.W. Foote.

Non-type material examined: Adults (over 300 specimens from the following localities): Dominica. St. Joseph, Springfield estate; West area experimental station; Parish of St Mark, 4km N Soufriere; Clarke Hall Est, Toucari, Cabrit Swamp, Layou Valley, Pont Casse. Some specimens were taken on human feces, and specimens were taken in the months of March, April, June, July, August and December. Immatures (several larvae and puparia along with associated adults): St. Paul Parish, Springfield Plantation, ex coconut Cocos mucifera , 21.May.2005, J. A. Korecki, P. Adler.

Comments: This apparently common Dominican species shows sexual dimorphism in the differently pigmented abdominal pleura and differently pigmented fore first tarsomeres of the male and female. It is easily distinguished from the less common Grallipeza footei by the lightly pigmented wings and unmodified fore tarsomeres. Grallipeza footei has been collected at the same places as G. spinuliger (Pont Casse, Clarke Hall) but not on the same dates.

Figures

FIGURES 82 – 87. Grallipeza spinuliger. 82, spermathecae and ducts; 83, male head lateral; 84, female dorsal photo by R. Lamb and P. MacKay; 85, epandrium and associated structures left dorsolateral, ejaculatory apodeme and duct missing; 86, male sternite 5; 87, epandrium and associated structures left lateral, stained. Abbreviations: ce, cercus; cd, common duct of spermathecae; d, distiphallus; ea, ejaculatory apodeme; ep, epandrium; epa, anteroventral epandrial arm; hy, hypandrium; ph, phallapodeme; ps, paired spermathecae; sd, single spermathecal duct.