Notiothereva Metz and Irwin

Notiothereva Metz and Irwin (Metz et al. 2003:242 orig. desc.). Type species Thereva albiventris Philippi (1865:770) by original designation.

Systematic Position. Phylogenetically Notiothereva falls within the Thereva ­group (Metz 2002:Fig. 2.8) of the higher Therevinae, which also includes the genera: Baryphora Loew, Caenopthalmus Kröber, Euphycus Kröber, Pseudothereva Lyneborg, Thereva Latreille, and Xestomyzina Kröber. This group shares the synapomorphies of having setae on the metanepisternum; setae on the posterior surface of the midcoxa; the length of the spermathecal sac duct greater than three times the length of the spermathecal sac; and the ejaculatory apodeme orientated posteriorly within the aedeagus and into the basiphallus (Metz 2002). Within the Therevinae Notiothereva possesses the autapomorphic characteristic of having incrassate maxillary palpi, the inner gonocoxal process directed posterolaterally, and the spermathecal sac duct over three times longer than spermathecal sac. Within the Thereva genus­group, Notiothereva shares a sister­group relationship with the South African genus Pseudothereva based on the synapomorphy of the setae surrounding the posterior thoracic spiracle being branched (Metz 2002).

Diagnosis. Body length males 5.3–8.4 mm (n=49), females 5.7–9.4 mm (n=44).

Head. Ocellar tubercle dark reddish brown, pruinescence gray, not raised above level of vertex; setae black, elongate. Male eyes holoptic, ommatidia smaller ventrally and laterally with distinct line of demarcation, female eyes dichoptic. Frons pruinose, setose; female frons of N. bezzii with dark reddish brown, glossy calli. Antenna shorter than head length; scape cylindrical, longer than wide, over twice length of pedicel, narrower than flagellum, setae absent medially, macrosetae dark reddish brown; pedicel globular, wider than long; flagellum with three flagellomeres, first flagellomere oval, tapered to second flagellomere, posterobasal setae short, dark brown, second flagellomere short, cylindrical, third flagellomere cylindrical, longer than second flagellomere, tapered apically, apical spine short, flagellum about 2.0 times length of scape. Face only slightly projecting beyond anterior margin of eyes. Parafacial with or without setae. Maxillary palpus cylindrical, apex rounded. Gena with or without anterodorsal patch of short, dark setae. Postocular macrosetae dark brown, in single row.

Thorax. Macrosetae 2–3 np, 1–2 sa, 1 pa, 1–2 dc, 0–2 sc. Postpronotal lobe concolorous with mesonotum. Cervical sclerite setae present or absent. Prosternum with white, elongate setae. Pleuron with setae elongate on propleuron, anepisternum, anterior half of katepisternum, laterotergite, scutellum, and metanepisternum; absent on proepimeron, anepimeron, meron, and and metakatepisternum. Wing. Setulae absent on R1. Cell r­m at middle of dc. M1, M2, and M3 originate separately from apex of dc. Cell m 3 open widely or closed, petiolate. Anal angle broadly rounded. Alula rounded. Legs. Posterior half of midcoxa with setae; hindcoxa with anterior papillate projection; apical macrosetae dark reddish brown, forecoxa lacking subapical, anterior macrosetae, hindcoxa with single lateral macroseta. Femora with anteroventral and posteroventral macrosetae.

Abdomen. Terminalia . Male. Tergite 8 (Fig. 1) bilobed, posterior margin deeply emarginate; median length short. Epandrium (Fig. 1) quadrate, broad basally; distinctly shorter medially than wide; anterior margin moderately emarginate; posterolateral margin short, broadly pointed, lacking pale glabrous margin; lateral view (Fig. 2) quadrangular, posteroventral margin expanded ventrally. Cerci (Fig. 1) free, oblong, apex rounded; ending distal to apex of epandrium. Hypoproct (Fig. 1) quadrate, ending distal to apex of epandrium; apicoventral area flat. Hypandrium (Fig. 3) pale brown, sclerotized.

Gonocoxite (Figs. 3–4) separated medially, basal three­fourths lobate, rounded laterally, apical fourth tapered to broad point posteriorly, macrosetae dark reddish brown on short, posterior tubercle; inner gonocoxal process directed posterolaterally, clavate apically; gonocoxal apodeme short, not extending beyond anterior margin of gonocoxite; gonocoxal bridge absent. Gonostylus (Fig. 4) sinuate with scattered dorsal setae. Aedeagus with dorsal apodeme (Fig. 5) oval, anterior margin narrowed, slightly projecting anteriorly; ventral apodeme (Fig. 6) narrow, not extending beyond anterior margin of dorsal apodeme; distiphallus (Fig. 5) broad basally, tapered posteriorly; ejaculatory apodeme (Fig. 5) with posterior half narrow, slightly bulbous posteriorly, anterior half expanded, not extending beyond anterior margin of dorsal apodeme, in cross­section flattened dorsoventrally. Lateral ejaculatory processes (Fig. 5) triangular, heavily sclerotized. Female. Anterior margin of sternite 8 truncate; aedeagal guide present posteromedially. Median lobe of tergite 9 lacking setae. Furca (Fig. 8) quadrate, anterior and posterior margins closed; anteromedial and posteromedial projections absent. Common spermathecal duct shorter than furca. Spermathecal sac duct narrow, elongate, greater than three times length of spermathecal sac. Two spherical spermathecae.

Distribution. Notiothereva is known from Argentina, Chile, and Peru.

Immature stages. The larvae of Notiothereva bezzii have been reared to adults but not described.

Included species: Notiothereva albiventris (Philippi), N. argentina Webb, N. aurea Webb, N. bezzii (Kröber), N. brunnipes (Kröber), and N. simulata (Malloch) .

Habitats and Temporal Phenology. Adults of Notiothereva have been collected using hand­nets, Malaise, pan, and pitfall traps in a wide variety of habitats including gullies and washes, along streams, along dry plains, and in Nothofagus forest. Adults have been collected from October to April, but most abundantly in November and December.