Litolinga Irwin and Lyneborg

Webb, Donald W., 2009, A revision of the genera Acrosathe Irwin and Lyneborg, Arenigena Irwin and Lyneborg, and Litolinga Irwin and Lyneborg (Diptera: Therevidae: Therevinae) from the Nearctic Region, Zootaxa 2091 (1), pp. 1-67 : 56-57

Litolinga Irwin and Lyneborg

Litolinga Irwin and Lyneborg (1981a:201 key, 234 diag., 236 spec. list; 1981b:519 key). Type species Psilocephala acuta Adams (1903:222) by original designation.

Litolinga contains two species and is characterized by male ocellar tubercle being distinctly raised above the level of the vertex; the male and female frons being covered with pubescence; the scape narrower or subequal to width of flagellum; the parafacial lacking setae; the gena projecting ventrally as a dark brown wedge; the cervical sclerite lacking macrosetae; the central depression of the prosternum and the posterior surface of the midcoxa setose; the macrosetae on the mesonotum dark reddish brown; with one pair of scutellar macrosetae; the wing cell m 3 widely open; and the male distiphallus lacking a deep apical cleft.

Moderately large flies, males 6.2–8.4 mm (n=20), females 6.3–10.4 mm (n=20). Male ocellar tubercle raised above level of occiput. Male eyes holoptic (separated by distance less than width of median ocellus); ommatidia smaller ventrally and laterally. Female frons with pair of large, dark brown, pubescent areas dorsolaterally; frontal setae absent on males, setae absent lateral to antennal base. Face slightly projecting beyond eyes. Antenna shorter than head length; scape cylindrical, longer than wide, over two times length of pedicel, subequal to or wider than flagellum, setae absent medially; pedicel wider than long, setae dark brown, short, absent medially; flagellum oval, apical third narrow, cylindrical, second flagellomere cylindrical, short, third flagellomere cylindrical, over four times longer than second flagellomere, pointed apically, flagellum over two times longer than wide, longer than length of scape. Parafacial setae absent. Gena sharply projecting ventrally with anteroventral patch of short, brown setae. Maxillary palpus cylindrical, apex rounded. Postocular macrosetae dark brown, elongate in single row, extending ventrally at lateral end. Macrosetae dark brown, sparse.

Thorax. Macrosetae 2–4 np, 1–2 sa, 1 pa, 0–1 (generally 0) dc, 0–2 sc ( Irwin and Lyneborg (1981a) characterized Litolinga with only one pair of scutellar macrosetae, but this proved to be a variable character). Postpronotal lobe concolorous with mesonotum; setae white, elongate. Setae present on cervical sclerite (macrosetae absent), in and around central depression of prosternum, on propleuron, anepisternum, katepisternum, laterotergite, and scutellum; setae absent on proepimeron, anepimeron, meron, and metanepisternum. Wing. Setulae absent on R 1. Cell m 3 widely open. Cell cup closed, petiolate. Halter stalk yellow, knob brown to dark brown. Legs. Metakatepisternum without setae. Coxae with setae on posterior half of middle coxa; hind coxa with papillate anterior projection; apical macrosetae dark brown, hindcoxa with 1 posterolateral macroseta. Male terminalia dark brown. Tergite 8 ( Figs. 98 , 106), bilobed, anterior margin broadly emarginate, posterior margin deeply emarginate. Sternite 8 ( Figs. 99 , 107) quadrate, sides tapered posteriorly; setae in band across posterior margin. Epandrium ( Figs. 98 , 106) quadrate, wider medially than long; anterior margin concave; setae dark brown. Cerci ( Figs. 98 , 106) free, ending distal to posterolateral margin of epandrium and above apex of hypoproct. Hypoproct ( Figs. 98 , 106), posterior margin slightly emarginate; ending below or slightly basal to apex of cerci; apicoventral area flat. Hypandrium ( Figs. 99 , 107) narrow, strap-like. Gonocoxite ventral view ( Figs. 99 , 107) separated medially, quadrate, median margin slightly emarginate, extending into narrow, attenuated ventral lobe ( Figs. 99 , 107), posterior margin emarginate, extending posterolaterally to bluntly pointed gonocoxal process, inner gonocoxal process and macrosetae absent; dorsal view, gonocoxal apodeme narrow, not extending anteriorly beyond anterior margin of gonocoxite; lateral view ( Figs. 100 , 108) oblong, posterior margin tapered to broad point. Gonostylus ( Fig. 101 ) sinuate with mediolateral expansion. Aedeagus with dorsal apodeme ( Figs. 102 , 109) quadrate or broadly expanded laterally, anterior margin truncate; ventral apodeme ( Figs. 103 , 110a) not reaching anterior margin of dorsal apodeme; distiphallus dorsal view ( Figs. 102 , 109) broad basally, tapered posteriorly. Female terminalia. Sternite 8 oval, sides rounded, anterior margin with anteromedial projection; aedeagal guide dark brown, heavily sclerotized. Median lobe of tergite 9 setose. Furca ( Figs. 105 , 112) closed posteriorly, sides sinuate, anteromedial, posteromedial, and anterolateral projections absent. Common spermathecal duct shorter than length of furca; spermathecal ducts originating from common spermathecal duct at junction of spermathecal sac. Two spermathecae.

Immature stages. The immature stages of Litolinga acuta have been reared but not described.

Biology. Litolinga occurs primarily in the southern Nearctic Region and has been hand-netted on sand dunes and sweep-netting grasses; collected from tortoise burrows; at blacklights set on sand dunes and in oakpine forest; Malaise traps set in xeric oak scrub, sand pine, turkey oak, and on sand dunes; in a Steiner trap; and pitfall traps set in sand pine and rosemary scrub. Adults have been generally collected throughout the year although L. acuta has not been collected in January and February.

Species included

Litolinga acuta (Adams)

Litolinga tergisa (Say)

Figures

FIGURES 98–105. Litolinga acuta. 98. Tergite 8, epandrium, cerci. 99. Sternite 8, gonocoxite ventral view. 100. Gonocoxite, lateral view. 101. Gonostylus lateral view. 102. Aedeagus, dorsal view. 103. Aedeagus, ventral view. 104. Aedeagus, lateral view. 105. Female internal reproductive organs.