Microthereva argentiventris Malloch

Webb, Donald W., 2006, The neotropical genera Microthereva Malloch and Peralia Malloch (Diptera: Therevidae: Therevinae), Zootaxa 1295, pp. 1-27 : 6-9

Microthereva argentiventris Malloch

( Figs. 1–10 , 30 )

argentiventris Malloch (1932: 245 male /fem. desc., Fig. 20 a ant.) ( Microthereva ). Type locality Argentina, Río Negro, Puerto Blest. Holotype male in BMNH.

Diagnosis

Microthereva argentiventris is separated from M. variventris by the characters in the key as well as the posterolateral margin of the male epandrium being short, rounded ( Fig. 2 ); the cerci ending above the posterior margin of the hypoproct ( Fig. 2 ); gonocoxite in lateral view spherical ( Fig. 5 ); anterior margin of dorsal apodeme truncate ( Fig. 7 ); ventral apodeme extending to anterior margin of dorsal apodeme ( Fig. 8 ); distiphallus in lateral view recurved posteriorly ( Fig. 9 ) with subapical hood; posterior half of ejaculatory apodeme broad, globular ( Fig. 7 ); female abdomen dark reddish brown, glossy, pruinescence gray, dense on posterolateral area of tergites 2–6.

Redescription of male

Variation (n=10) Body length 5.8–7.7, 6.8 mm.

Head. Length 0.84–1.12, 1.10 mm. Frons dark reddish brown, pruinescence gray; setae dark reddish brown. Antenna dark brown, pruinescence gray, dense on scape and pedicel; antenna/head length 0.65–0.90, 0.81; scape length 0.34–0.44, 0.38 mm, width 0.14–0.18, 0.17 mm, length/width 1.9–2.8, 2.2, scape/pedicel length 2.8–4.2, 3.8, scape/ flagellum width 0.78–1.13, 0.99, setae dark brown, elongate; pedicel length 0.08–0.12, 0.10 mm, width 0.14–0.18, 0.16 mm, length/width 0.56–0.62, 0.57; flagellum fusiform ( Fig. 1 ), length 0.34–0.46, 0.40 mm, width 0.16–0.18, 0.17 mm, length/width 2.1–2.6, 2.3, flagellum/scape width 1.0–1.2, 1.1. Parafacial dark brown, pruinescence white; setae dark brown. Maxillary palpus brown, pruinescence whitish gray; length 0.44–0.64, 0.52 mm, width 0.08–0.10, 0.09 mm, length/width 4.6–8.0, 5.6; setae white. Genal setae white. Occipital setae white, elongate becoming dark brown dorsally. Macrosetae (>40) dark brown to black, scattered. Postocular macrosetae longer than occipital macrosetae, in single row.

Thorax. Macrosetae 3–5 np, 2 sa, 1 pa, 2–4 dc, 2 sc. Mesonotum dark brown, pruinescence gray; vittae dark brown, dull, separated by gray pruinescent lines; setae dark brown, elongate, erect. Postpronotal setae dark brown, elongate. Pleuron dark brown, pruinescence gray; setae white on propleuron, ventral half of anepisternum, katepisternum, laterotergite, and metanepisternum, dark brown on scutellum and dorsal half of anepisternum. Wing. Membrane pale brown; veins dark brown; length 5.5–7.0, 6.3 mm, width 1.2–2.3, 1.9 mm, length/width 3.0–5.3, 3.5; pterostigma dark brown. Halter brown. Legs. Coxae dark brown, pruinescence white, dense; setae white; apical macrosetae pale yellow on fore­ and hindcoxa, dark reddish brown on midcoxa; hindcoxa with one dark reddish brown posterolateral macrosetae. Femora dark reddish brown, pruinescence white; ventral setae white; av 0:0:1, pv 0:0:0.

Abdomen. Dark reddish brown, pruinescence white, dense; dorsal setae white intermixed with dark brown setae on posterior tergites; lateral setae white, elongate becoming dark brown on posterior segments. Terminalia (MEI 028430). Dark brown. Tergite 8 ( Fig. 2 ), setae pale brown; median length thick (0.14 mm). Sternite 8 ( Fig. 3 ), quadrate, posterior margin broadly emarginate; setae dark brown, absent medially on posterior margin. Epandrium ( Fig. 2 ), posterolateral margin short, broadly pointed; setae dark brown. Cercus ( Fig. 2 ), ending basal to apex of hypoproct. Hypoproct ( Fig. 2 ), posterior margin slightly emarginate, ending distal to apex of cercus. Gonocoxite ventral view ( Fig. 3 ) dark brown, posterolateral margin slightly tapered to broad point, setae yellowish brown and dark brown; inner gonocoxal process ( Figs. 3–5 ) dark yellow, sinuate, setae dark yellow; dorsal view ( Fig. 4 ); lateral view ( Fig. 5 ) broad, globular. Gonostylus lateral view ( Fig. 6 ) broad, sinuate with two apical points, setae dark yellow. Aedeagus with dorsal apodeme ( Fig. 7 ) quadrate, posterolateral margin projecting laterally, anterior margin truncate with short anterolateral projection; ventral apodeme ( Fig. 8 ), divergent anteriorly, anterior margin truncate, reaching anterior margin of dorsal apodeme; distiphallus dorsal view ( Fig. 7 ) broad basally, tapered posteriorly, lateral view ( Fig. 9 ) short, thick, subapical hood bearing small apical spines; ejaculatory apodeme ( Fig. 7 ), posterior half large, expanded, globular, anterior half narrow, slightly expanded anteriorly.

Female

Similar to male except for following.

Variation (n=10)

Body length 8.6–9.8, 9.1 mm.

Head. Length 1.08–1.30, 1.20 mm. Frons pruinescence brownish gray; setae dark brown to black. Antenna/head length 0.72–0.89, 0.81; scape length 0.36–0.48, 0.41 mm, width 0.16–0.20, 0.18 mm, length/width 1.8–2.5, 2.3, scape/pedicel length 3.3–6.0, 4.1, scape/flagellum width 0.94–1.25, 1.10; pedicel length 0.08–0.12, 0.10 mm, width 0.14–0.18, 0.16 mm, length/width 0.50–0.75, 0.63; flagellum length 0.42–0.52, 0.45 mm, width 0.16–0.18, 0.17 mm, length/width 2.3–2.9, 2.6, flagellum/scape width 1.0–1.3, 1.1. Parafacial dark brown, pruinescence white; setae dark brown. Maxillary palpus brown, pruinescence whitish gray; length 0.52–0.60, 0.57 mm, width 0.10 mm, length/width 5.2–6.0, 5.7; setae white. Genal setae white. Occipital setae white, elongate, becoming dark brown dorsally; macrosetae approximately 15.

Thorax. Macrosetae 4–5 np, 1–3 sa, 1 pa, 1–2 dc, 2 sc. Wing. Length 6.8–8.0, 7.3 mm, width 2.2–2.5, 2.3 mm, length/width 3.0–3.3, 3.2. Legs. Coxae with apical macrosetae dark reddish brown. Anteroventral macrosetae 0:0:0–1, pv 0:0:0.

Abdomen. Dark reddish brown, glossy, pruinescence white, dense laterally on tergites 1–7; dorsal setae dark brown to black with white setae laterally on tergite 1. Terminalia (MEI 028432). Furca and internal reproductive complex ( Fig. 10 ), furca length 0.61 mm, width 0.31 mm.

Distribution

Microthereva argentiventris is distributed in western Argentina and Chile ( Fig. 30 ).

Habitats and phenology

Microthereva argentiventris has been collected from November to January.

Specimens examined

Type specimen. The holotype male of Microthereva argentiventris Malloch is labeled "L. Nahuel Huapi, Puerto Blest, 2–3.xii.1926, Argentina Terr. Rio Negro, F. & M. Edwards" and is in the BMNH (Type No. BMNH (E) 241998). Other specimens. ARGE NTINA. RIO NEGRO. 1 km N Villa Mascardi, Lago Mascardi [­41.35, ­71.517], 850 m, 18.XI.1966, Irwin, M.E., Schlinger, E.I., 6Ψ MEI 028431–2, 147514–7 ( MEIC); Bariloche [­41.15, ­71.3], –. XI.1926, Shannon, R.C. & E., 6♂, MEI 0 28430, 112418, 128989, 147505–6, 1475010, 1Ψ 147509 ( USNM). NEUQUEN. 6 km N San Martin de Los Andes [­ 40.106, ­71.36], 1000 m, 1–4.I.1994, Wood, G. & M., 1♂ MEI 123799 ( CNC); slope of Cerro Chapelco, San Martin de Los Andes [­40.167, ­71.35], 1500 m, 28.XI.1989, Marshall, S.A., 2♂ MEI 147511 ( DEBU), 147536 ( INHS), 2Ψ 147537 ( INHS) 147538 ( DEBU). CHILE. ARAUCANIA. Termas de Rio Blanco, 1080 m, 22.I.1967, Irwin, M.E., Stange, L.A., 1♂ MEI 0 28429 ( MEIC); 33 km E Pucon, Termas de Palquin [­39.267, ­ 71.67], 680 m, 10–12.XI.1989, Marshall, S.A., 1♂ MEI 147512 ( DEBU); Lonquimay, Cordilleras Las Raices [­37.883, ­71.183], 1500–1800 m, 25–28.XII.1967, Peña, L.E., 1Ψ, MEI 147513 ( MEUC). BIO­BIO. Las Trancas [­36.927, ­71.606], 21.XI.1964, Peña, L.E., 2Ψ MEI 0 79708, 0 79711 ( CNC); 21–30.XI.1964, 2♂ MEI 0 74217, 0 79712 ( CNC); 6.XII.1964, 1Ψ MEI 147518 ( MEIC).

Figures

FIGURES 1 – 10. Microthereva argentiventris. 1. Antenna. 2. Tergite 8, epandrium, cerci, hypoproct, dorsal view. 3. Sternite 8, gonocoxite, ventral view. 4. Gonocoxite, dorsal view. 5. Gonocoxite, lateral view. 6. Gonostylus, lateral view. 7. Aedeagus, dorsal view. 8. Aedeagus, ventral view. 9. Aedeagus, lateral view. 10. Female internal reproductive organs. Scale = 0.1 mm. Abbreviations: C = cercus, CD = common duct, DA = dorsal apodeme, Dp = distiphallus, EA = ejaculatory apodeme, Epa = epandrium, F = furca, Gs = gonostylus, Gx = gonocoxite, H = hypandrium, Hpt = hypoproct, Igp = inner gonocoxal process, Sp = spermatheca, Spd = spermathecal duct, SpS = spermathecal sac, SS = sensory seta, S 8 sternite 8, T 8 = tergite 8, VA = ventral apodeme, VL = ventral lobe.

FIGURES 30 – 32. Distribution maps. 30. Microthereva argentiventris (closed circles), M. variventris (arrow). 31. Peralia hermanni. 32. Peralia vittata.

FIGURES 20 – 29. Peralia vittata. 20. Tergite 8, epandrium, cerci, hypoproct, dorsal view. 21. Sternite 8, gonocoxite, ventral view. 22. Gonocoxite, dorsal view. 23. Gonocoxite, lateral view. 24. Gonostylus, lateral view. 25. Aedeagus, dorsal view. 26. Aedeagus, ventral view. 27. Aedeagus, lateral view. 28. Female internal reproductive organs. Peralia hermanni. 29. Female internal reproductive organs. Scale = 0.1 mm. Abbreviation: LEP = lateral ejaculatory process, SpSd = spermathecal sac duct.