Lysilinga Irwin and Lyneborg

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 : 200-206

Lysilinga Irwin and Lyneborg

Lysilinga Irwin and Lyneborg (1981a:230 orig. desc.; 1981b:519). Type species: Psilocephala aurantiaca Coquillett (1904:177) .

Diagnosis

Lysilinga is characterized by lacking setae on the metakatepisternum; the distiphallus with a distinct subapical hood (Fig. 432); the male gonostylus with one apical point ( Fig. 402); the male ventral lobe greatly reduced, not wrapping around gonostylus; the dorsal and ventral apodemes of the male aedeagus flattened dorsoventrally in cross­section; and the female furca with a posteromedial projection ( Fig. 441).

Redescription of genus

Moderate sized flies, males 4.8–10.4 mm (n=57), females 4.8–8.8 mm (n=56).

Head. Ocellar tubercle dark reddish brown to black, pruinescence gray; setae dark reddish brown to black, short. Males holoptic, separate medially by distance less than width of median ocellus, female dichoptic. Frons small in males, broad in females; black pruinescent band and setae absent lateral to antennal base. Face slightly projecting beyond eyes. Antenna shorter than length of head, scape cylindrical, longer than wide, over 2 times length of pedicel, width narrower than width of flagellum, macrosetae on scape dark reddish brown to black; pedicel spherical, setae dark reddish brown, short; first flagellomere expanded laterally then tapering to attenuate apex, second flagellomere cylindrical, third flagellomere short, cylindrical, tapered apically, apical style short, flagellum longer than wide, 1–2 times length of scape. Parafacial setae absent. Maxillary palpus cylindrical, apex rounded, length more than 5 times longer than wide; setae elongate. Genal setae white, elongate. Occiput convex, dark reddish brown to black, pruinescence gray; setae elongate on ventral half, macrosetae dark reddish brown to black. Postocular macrosetae dark reddish brown to black, in single row.

Thorax. Macrosetae males 3 np, 1–2 sa, 1 pa, 0–2 dc, 1–2 sc, females 3 np, 1–2 sa, 1 pa, 0–2 dc, 1–2 sc. Vittae indistinct; postpronotal lobe concolorous with dorsum; prosternum with white elongate setae in and around central depression. Pleural setae elongate on propleuron, anepisternum, laterotergite, metanepisternum, and scutellum, present or absent on katepisternum, absent on proepimeron, anepimeron, meron, and metakatepisternum. Wing. Setulae absent on R 1; M 1, M 2, and M 3 originate separately from apex of dc; cell cup closed, petiolate; anal angle broadly rounded. Legs. Coxa setae white, elongate; setae present on posterior half of middle coxa; hind coxa with dark reddish brown anterior knob and one posterolateral macroseta; apical macrosetae dark brown. Femoral setae filiform ventrally becoming lanceolate, appressed dorsally; anterovental macrosetae on males 0–3:0–1:0–12, females 0:0:0–9, pv on males 0:0:0–9, females 0:0:0–7.

Abdomen. Male terminalia . Tergite 8 ( Figs. 361–370) bilobed, anterior margin emarginate, posterior margin deeply emarginate; narrow medially (0.02 mm); setae absent medially on posterior margin; one pair of sensory sensilla. Sternite 8 (Figs. 371–380), sides rounded, posterior margin emarginate; sensory sensilla 1–2. Epandrium ( Figs. 361–370) quadrate, broad basally, tapering apically; shorter medially than wide; anterior margin emarginate; posterolateral margin short, broadly pointed. Cercus ( Figs. 361–370) oblong, apex rounded. Hypoproct ( Figs. 361–370) quadrate, flat, ending distal to posterolateral margin of epandrium, apicoventral area flat. Hypandrium narrow, strap­like. Gonocoxite ventral view (Figs. 371–380) separated medially, rounded laterally; dorsal view ( Figs. 381–390) gonocoxal apodeme narrow, not extending beyond anterior margin of gonocoxite, inner gonocoxal process and posteromedial lobe absent; ventral lobe large, broadly rounded, not wrapping around base of gonostylus. Gonostylus ( Figs. 401–410) with basodorsal lobe variable, generally absent or greatly reduced; apical three­fourths falcate, recurved apically to form one point. Aedeagus with dorsal apodeme (Figs. 411–420) quadrate to oval, anterior margin truncate; ventral apodeme ( Figs. 421–430) narrow, tapering to point anteriorly; distiphallus dorsal view (Figs. 411–420) short, broad basally, lateral view (Figs. 431–440) with subapical hood; ejaculatory apodeme variable. Female terminalia . Sternite 8 quadrate, tapered posteriorly to broad point with posteromedial incision; aedeagal guide absent; anterior margin lacking anteromedial projection. Setae absent on median lobe of tergite 9. Furca ( Figs. 441–447) oblong to quadrate. Spermathecal ducts ( Figs. 441–447) directed anteriorly, narrow, sac­like basally then becoming thread­like anteriorly. Spermathecal sac oblong, narrow posteriorly. Two spermathecae, oval to spherical.

FIGURES 371–380. Male sternite 8, gonocoxite ventral view. 371. aurantiaca . 372. chamela . 373. crassiseta . 374. digita . 375. dolichophalla . 376. nigra . 377. occipitalis . 378. parkeri . 379. pilifrons . 380. recta . Scale = 0.1 mm.

FIGURES 391–400. Gonocoxite, lateral view, 391. aurantiaca . 392. chamela . 393. crassiseta . 394. digita . 395. dolichophalla . 396. nigra . 397. occipitalis . 398. parkeri . 399. pilifrons . 400. recta . Scale = 0.1 mm.

FIGURES 411–420. Aedeagus, dorsal view. 411. aurantiaca . 412. chamela . 413. crassiseta . 414. digita . 415. dolichophalla . 416. nigra . 417. occipitalis . 418. parkeri . 419. pilifrons . 420. recta . Scale = 0.1 mm.

FIGURES 431–440. Aedeagus, lateral view. 431. aurantiaca . 432. chamela . 433. crassiseta . 434. digita . 435. dolichophalla . 436. nigra . 437. occipitalis . 438. parkeri . 439. pilifrons . 440. recta . Scale = 0.1 mm.

Immature stages Unknown.

Distribution Lysilinga is distributed from the southwestern United States through Costa Rica.

Habitats and phenology

Lysilinga is distributed in semi­arid areas. Specimens have been handnetted and collected in Malaise and light (ultraviolet, argon) traps in dry washes (near springs or wet areas), in chaparral, or in coastal sage scrub, and on a variety of plants ( Acacia greggii Gray , Chilopsis linearis (Cav.) Sweet , an orchidaceous legume tree, Sapindus sp. ). Adults have been collected throughout the year except in October, December, and January.