Brachylinga albifrons Webb, 2006

Webb, Donald W. & Metz, Mark A., 2006, A Revision of the New World Genera Brachylinga Irwin and Lyneborg and Lysilinga Irwin and Lyneborg (Diptera: Therevidae: Therevinae) with the Description of a New Genus, Elcaribe Webb, Zootaxa 1288 (1288), pp. 1-241 : 18-19

Brachylinga albifrons Webb spec. nov.

( Figs. 2, 25, 48, 71, 94, 117, 140, 163, 214)

Etymology

Albus (Latin) = white. This name is used as an adjective and refers to the white pruinescence and setae on the male frons.

Diagnosis

Brachylinga albifrons is taxonomically associated with B. cinerea and B. pavida in having the male frons setose; the male parafacial uniformly gray; in lacking an anterodorsal patch of short, dark reddish brown setae on the gena; and in lacking setae on the katepisternum. Brachylinga albifrons differs from B. cinerea and B. pavida in having the halter knob yellow; the epandrium with dark yellow setae on the posterolateral margin ( Fig. 2); the gonocoxite in ventral view ( Fig. 25) with dark yellow setae anteromedially; and the distiphallus ( Fig. 163) curved ventrally at a 90° angle.

Description of holotype male (MEI 048198)

Body length 6.2 mm.

Head. Length 0.74 mm. Ommatidia of uniform size. Frons pruinescence white ventrally, pale yellowish brown dorsally; setae dark reddish brown. Antenna/head length 0.80; dark reddish brown, pruinescence gray on scape; scape length 0.18 mm, width 0.12 mm, length/width 1.5, scape/pedicel length 2.3, scape/width 0.75, setae dark brown, short; pedicel length 0.08 mm, length/width 0.7; flagellum length 0.33 mm, width 0.16 mm, length/width 2.1, flagellum/scape length 1.8. Parafacial pruinescence gray. Maxillary palpus absent on specimen. Genal setae white. Occipital setae white becoming lanceolate, appressed dorsally. Postocular macrosetae dark reddish brown.

Thorax. Macrosetae dark reddish brown, 4 np, 1 sa, 1 pa, 2 dc, 2 sc. Mesonotum pruinescence gray; setae dark brown, short, erect intermixed with white, lanceolate, appressed setae. Pleuron and scutellum dark reddish brown, pruinescence white; setae white on propleuron, anepisternum, metanepisternum, laterotergite, and scutellum, absent on katepisternum. Wing. Membrane pale gray, veins brown; length 4.5 mm, length/width 2.8; pterostigma indistinct; cell m 3 closed, petiolate. Halter pale yellow. Legs. Coxa setae white, present on posterior surface of midcoxa; macrosetae dark reddish brown. Forefemur reddish brown, pruinescence white, mid­ and hindfemora dark yellow, hindfemur slightly reddish brown dorsally; ventral setae white intermixed with dark brown setae apically on forefemur; av 2:0:4, pv 0:0:6. Tibiae dark yellow. Tarsomeres 1–2 dark yellow; 3–5 reddish brown.

Abdomen. Tergite 1 dark brown, tergites 2–8 yellow, pruinescence white; dorsal setae white, appressed; lateral setae white. Terminalia . Dark yellow. Tergite 8 ( Fig. 2), narrow medially (0.02 mm); setae dark yellow, absent medially on posterior margin. Sternite 8 ( Fig. 25) quadrate, sides slightly diverging, posterior margin emarginated; setae absent medially on posterior margin. Epandrium ( Fig. 2), sides rounded; setae dark yellow, aggregated on posterolateral corner. Cercus ( Fig. 2) ending at apex of posterolateral margin of epandrium, basal to apex of hypoproct. Hypoproct ( Fig. 2), quadrate, posterior margin slightly emarginate, ending distal to apex of cercus. Gonocoxite ventral view ( Fig. 25), anterior half rounded, extending apically into large, rounded, glabrous lobe before becoming attenuate apically; setae dark yellow with anteromedial aggregation, apical macrosetae dark brown; dorsal view ( Fig. 48) posteromedial lobe short, rounded, gonocoxal bridge absent; lateral view ( Fig. 71) oblong, tapering apically to broad, rounded point; ventral lobe ( Fig. 25) with ventral spines. Gonostylus ( Fig. 94), basodorsal lobe moderately large, rounded; ventral margin straight, setae dark yellow, extending apically in distinct tuft; fine, short spines absent laterally. Aedeagus with dorsal apodeme ( Fig. 117) quadrate, posterolateral margin slightly expanded; ventral apodeme ( Fig. 140) tapering anteriorly, ending at anterior margin of dorsal apodeme; basiphallus with short dorsal carina; distiphallus ( Fig. 117) tapered apically, lateral view ( Fig. 163) curved ventrally at 90° angle, apicolateral spines small; ejaculatory apodeme ( Fig. 117), anterior margin truncate.

Female Unknown.

Distribution Brachylinga albifrons is known from Venezuela ( Fig. 214).

Habitats and phenology Brachylinga albifrons was collected at a blacklight trap from 6–12 February.

Specimen examined

The holotype male (MEI 048198) of Brachylinga albifrons is labeled " Venezuela, Guár., 12 km S Calabozo [8.812, ­67.43], II–6–12–1969, P. & P. Spangler, at blacklight" and is deposited in the USNM .