Grallipeza nebulosa (Loew)

Marshall, S. A., 2013, Grallipeza Rondani (Diptera: Micropezidae: Taeniapterinae) of the Caribbean and North America, Zootaxa 3682 (1), pp. 45-84 : 67

Grallipeza nebulosa (Loew)

Figs. 38–44

Calobata nebulosa Loew, 1866: 108 .

Rainieria nebulosa, Cresson, 1930: 319 .

Grallipeza nebulosa, Hennig 1934: 307 ; Steyskal, 1967: 83; 1968: 48.7.

Description: Size: Approximately 7–8 mm. Colour: Head, including frontal vitta and palpus, almost entirely orange; ocellar triangle black, clypeus shining dark brown, anterior margin of orbital strips sometimes darkened. Most of fore femur (all but base) all of fore tibia brown, fore tarsomere 1 and basal 4/5 of tarsomere 2 yellow-white with pale setulae, apex of tarsomere 1slightly browned with brown setulae, remaining tarsomeres brown with dark setulae. Mid and hind femora orange with a brown apex and usually with an indistinct brown band in distal third. Tarsomere one of hind leg white, tarsomeres 2–5 pale brown. Thorax entirely orange, with silvery patch just below anterior spiracle, on anepisternum, and on posterodorsal part of katepisternum. Katepisternum with a double row of golden bristles. Female abdomen with tergite 1 pale reddish brown, tergites 2–5 dark reddish brown pollinose and densely setulose, tergite 6 lightly pollinose and sparsely setulose, oviscape heavily pollinose laterally and apically, dorsal part of basal half shining dark brown, sparsely but distinctly setulose. Abdominal pleuron of female entirely cream yellow to white, dorsal margin black. Male abdominal syntergite 1–2 light brown, tergites 3–5 brown pollinose and densely setulose, tergite 6 darker shining and sparsely setulose, epandrium elongate, covered with fine white setulae except for small ventral area at base, apex long-setose ventrally. Male abdominal pleuron dark laterally with a large circular white ventral area, segment 2 with a distinct, large, round, yellow-brown microsetulose membranous dome.

Head: Arista bare on distal third, basal half with short hairs only slightly longer than width of basal aristomere. Pedicel with long ventroapical bristles, one almost as long as first flagellomere. Lunule broad, 2 times scape width. Frontal vitta flat, parallel sided except at anterior margin where it joins the lower orbital margin to form a slightly differentiated transverse strip, lower orbital margins distinctly elevated.

Thorax: Cervical sclerite of male evenly convex; cervical sclerite of female ventrally almost flat, with a large dull differentiated area but without conspicuous pits. Fore femur with only small ventral setulae. Two distinct dorsocentral bristles, several small suprahumeral bristles part of a continuous row of dorsocentral setulae, usually only the first 2–3 distinctly enlarged. Postpronotum bare or with 1–2 small setulae. Wing: Anal cell bare. Discal band diffuse, forming an indistinct patch running from R4+5 to CuA1; membrane distal to patch evenly and lightly infuscated.

Female abdomen: Oviscape long, twice as long as tergite 6 and almost as long as preabdomen. Spermathecae and associated ducts ( Fig. 43 ) extremely distinctive, common duct expanded into a broad, almost parallel-sided distal area that branches into two broad, recumbent, elongate bell-shaped spermathecae; single spermatheca with three large and similar lobes.

Male abdomen: Genital fork ( Fig. 42 ) V-shaped at base, mesal surface of arms with widely spaced teeth on basal half and more closely spaced teeth distally, apex with sparse long hairs. Distiphallus short, broad basally, distally expanding into a robust bulb with a distinctive spherical basal part and a coiled distal part leading to a broad, tongue-like distal extension somewhat longer than the bulb itself ( Fig. 44 ).

Type material: Holotype (unique male, MCZ; photographs online http://insects.oeb.harvard.edu/mcz): “ Type 13328” “Loew Coll.” “Fa”.

Material examined (over 100 specimens including the following): Alabama. Baldwin Co, Bon Secour, Malaise, 19.ix.2004, E. Benton. Florida. Archbold Biological Station 4.xii.1985, S.A. Marshall; Highlands Hammock St. Pk, 17.iv.1989, S.A. Marshall; Pt. Charlotte, 20–25.xii.1997, S.A. Marshall; Sarasota, 20.xii.1999, S.A. Marshall. Georgia. Chatham Co., 27–31.viii.1951, H. Dodge. North Carolina. Greensboro, 22.xii. ??, C. Gardener. South Carolina. Georgetown Co., Hobcaw Barony, 25.iv–8.v.2004, J. Klymko; Charleston Co., Cape Romain N.W.R., Bull Island, 3.v.2004, S.A. Marshall.

Comments: This is the only Grallipeza species known from the United States, and it is distinctive from all sympatric Diptera . The combination of wing pigmentation, leg pigmentation and thoracic chaetotaxy render it distinctive from Caribbean congeners other than the Cuban endemic G. b a r a c o a. These species can be separated on the basis of fore tarsal colour and the pigmentation of the wing veins; details of the important female abdominal characters are not available for G. b a r a c o a. Male genitalia of these two species (as well as the other Cuban endemic, G. placida ) are strikingly similar and suggest a close relationship although the apex of the distiphallus is slightly different in each species (see Figs. 14 , 63 and 92 ). Cresson (1938) and Steyskal (1965) treated G. b a r a c o a and G. n e b u l o s a as synonyms, but Steyskal later (1967) recognized them as separate species.

Figures

FIGURES 38 – 44. Grallipeza nebulosa. 38, live male Florida; 39, live female Florida; 40, female right lateral; 41, female head and thorax dorsal; 42, male terminalia ventral; 43, spermathecae and ducts; 44, male terminalia left lateral.

FIGURES 13 – 14. Grallipeza baracoa. 13, live female, Baracoa, Cuba; 14, male epandrium and associated structures.

FIGURES 59 – 65. Grallipeza placida. 59, spermathecae and ducts; 60 – 61, live female, Santiago de Cuba; 62, live male, Santiago de Cuba; 63, epandrium and associated parts, left lateral; 64, phallic bulb; 65, male sternite 5.

FIGURES 88 – 93. Grallipeza turba. 88, female right lateral; 89, male left lateral; 90, spermathecae and ducts; 91, head dorsal; 92, epandrium and associated structures; 93, male sternite 5. Abbreviations: ce, cercus; cd, common duct of spermathecae; d, distiphallus; ea, ejaculatory apodeme; ep, epandrium; epa, anteroventral epandrial arm; hy, hypandrium; ph, phallapodeme; pog, postgonite; prg, pregonite; ps, paired spermathecae; sd, single spermathecal duct.