Ataenogera argentifrons sp. nov. (Figs. 10–19, 57) Etymology. Argentum (Latin) = silver; frons (Latin) = forehead. This species is characterized by the silver frons in males and females. Diagnosis. Ataenogera argentifrons shares with A. grandis, A. irwini, and A. minuta the absence of lanceolate setae on the male and female abdomens. It is separated from these species in having the frons with its sides almost parallel and possessing setae ventrolateral to the ocellar tubercle (Figs. 10–11); the male eyes separated by a distance twice as wide as ocellar tubercle and the ommatidia of equal size; the apical macrosetae on the coxa yellow; male hypandrium (Fig. 13) with setae across anterior fourth; male gonocoxite in dorsal view (Fig. 14) with large, falcate projection posteromedially; and the female furca (Fig. 19) broadly expanded anterolaterally. Description of male Variation (n=10). Body length 6.2–8.6, 7.5 mm. Head. Length 0.8–1.0, 0.9 mm. Eyes dichoptic (Fig. 10), separated by distance twice as wide as ocellar tubercle; ommatidia of equal size. Frons (Fig. 10) broad, quadrate, sides parallel, pubescence silver; setae black, short, ventrolateral to ocellar tubercle. Antenna dark brown or with first flagellomere gray brown, pubescence light gray, antenna/head length 1.7–2.2, 1.9; scape length 0.20–0.28, 0.24 mm, width 0.14–0.20, 0.17 mm, length/width 2.8–4.0, 1.4, scape/pedicel length 3.6–4.8, 3.0, scape/flagellum width 0.8–1.0, 0.9, setae black, short, macrosetae dark reddish brown; pedicel length 0.08–0.10, 0.08 mm, width 0.16–0.20, 0.17 mm, length/width 0.40–0.63, 0.49; flagellum narrow, elongate, length 1.26–1.44, 1.35 mm, width 0.16–0.24, 0.20 mm, length/width 5.1–8.4, 7.0, flagellum/scape length 4.8–6.7, 5.7. Maxillary palpus setae white. Occipital setae white, elongate, absent dorsomedially, macrosetae scattered on dorsal fourth of occiput. Thorax. Macrosetae 2 np, 1 sa, 1 pa, 0 dc, 1 sc. Mesonotum dark reddish brown, subshiny, pubescence dense gray in broad medial band and along lateral margin; vitta appear as dark reddish subshiny stripes separated by broad medial band of gray pubescence extending from pronotum to scutellum; setae black, short. Pleurae dark reddish brown, pubescence gray; setae pale yellow over entire anepisternum and laterotergite. Scutellum dark reddish brown, pubescence light gray; setae black, short, scattered on posterior margin. Wing. Length 5.5–6.5, 5.8 mm, width 1.5–2.2, 1.8 mm, length/width 3.0–3.3, 3.2. Membrane hyaline; pterostigma dark brown. Cell m3 closed, petiolate. Halter dark brown, posterior half of knob pale yellow. Legs. Coxa dark reddish brown, pubescence white, dense, setae pale yellow; apical macrosetae pale yellow extending around anterior margin of coxa, forecoxa with anterolateral macroseta, hindcoxa lacking posterolateral macroseta. Femora, tibiae and tarsi dark brown. Abdomen. Dark reddish brown, glossy, posterior margin of tergites 1–5 white to pale yellow; dorsal setae black, short, lateral setae pale yellow, elongate of tergites 1–2, short, black on remaining tergites; black lanceolate setae absent on abdominal tergites and sternites. Terminalia (MEI 107046). Epandrium (Fig. 12) brown, anterior margin truncate with small lateral emargination. Hypoproct ventral view (Fig. 12) broad, rounded posteriorly, not attached laterally to sides of epandrium; setae dark yellowish brown, scattered laterally. Hypandrium (Fig. 13) with dark brown setae across posterior fourth. Gonocoxite ventral view (Fig. 13), broad with outer gonocoxal process elongate, setae dark reddish brown, abundant along medial margin; dorsal view (Fig. 14) with large, falcate projection posteriorly. Gonostylus (Fig. 15) broad, sinuate with heavily sclerotized dark brown projection basodorsally. Aedeagus with dorsal apodeme (Fig. 16) broad basally; ventral apodeme (Fig. 17) heavily sclerotized, bifurcate, anterior margin deeply emarginate; distiphallus lateral view (Fig. 18) broadly curved ventrally. Female Similar to male except for following. Variation (n=8). Body length 7.3–9.8, 8.3 mm. Head. Length 0.98–1.20, 1.05 mm. Eyes separated by distance 2.1 times width of ocellar tubercle. Frons (Fig. 11). Antenna/head length 1.3–1.6, 1.5; scape length 0.20–0.36, 0.29 mm, width 0.14–0.18, 0.16 mm, length/width 1.6–2.3, 1.8, scape/pedicel length 2.0–3.6, 2.9, scape/flagellum width 0.78–1.13, 0.96; pedicel length 0.09–0.10, 0.10 mm, width 0.14–0.18, 0.15 mm, length/width 0.56–0.71, 0.65; flagellum length 1.00– 1.30, 1.14 mm, width 0.14–0.18, 0.17 mm, length/width 6.5–7.3, 6.9, flagellum/scape length 3.4–5.4, 4.0. Thorax. Macrosetae 2 np, 1 sa, 1 pa, 0–1 (rare) dc, 1 sc. Wing. Length 5.8–8.2, 6.9 mm, width 1.8–2.3, 2.0 mm, length/width 3.1–4.0, 3.4. Abdomen. Dark reddish brown, glossy, posterior margin of tergites 1–4 and 7–8 pale yellow; dorsal setae black, short, lateral setae pale yellow, elongate on tergite 1, short, black on remaining tergites; black lanceolate setae absent. Terminalia (MEI 108152). Furca (Fig. 19) strongly sclerotized, anterior margin closed with broad, lateral projection; length 0.29 mm, width 0.32 mm. Immature stages Unknown. Distribution Ataenogera argentifrons is known from Argentina (Fig. 57). Habitats and phenology Ataenogera argentifrons has been handnetted or collected in Malaise traps set in ravines during October and November. Specimens examined Type specimens. The holotype male of Ataenogera argentifrons sp. nov. (MEI 107064) is labeled " ARGENTINA: Catamarca Prov.; 2 km N Belén, Quebrada Belén @ dam, 3590 ft. 17/ 19–X–1997, malaise in dry hillside re[a]vine, ME Irwin, FD Parker, S Roig, 27.6159 S., 67.0130 W " (MEI 107064) and is deposited in the CAS (Type No. 18237). PARATYPES. ARGENTINA. CATAMARCA. 2 km N Belén, Quebrada Belén [- 27.616, -67.013], 1094m, 17–19.X.1997, MEI, FDP, Roig, S., 29♂ MEI 107044 (BMNH), 107046 (USNM), 107047 (CNC), 107048 (INHS), 107049 (CSCA), 107 0 50 (ZMHB), 107051 (MLUH), 1107052–107063, 107066–107072, 107074, 108153–4 (MEIC), 10Ψ 107065 (BMNH), 107073 (USNM), 107075 (CNC), 107077 (INHS), 1077078 (CSCA), 107079 (ZMHB), 107080 (MLUH), 107081, 108152, 108160 (MEIC), Malaise in dry hillside ravine, 2♂ 106889, 107045, 1Ψ 107076 (MEIC), Malaise in damp hillside ravine; San Pablo [-28.697, -66.043], 712m, 24.X–12.XI.2003, MEI, FDP, 2Ψ MEI 165130, 166967 (MEIC), Malaise trap in small dry wash. MENDOZA. Potrerillos [-32.95, -69.21], 6.I.1926, Edwards, F., Edwards, M., 1♂ MEI 0 0 5733 (BMNH). SALTA. 48 km N Cafayate [-25.8445, -65.7027], 26.X–13.XI.2003, 1408m, MEI, FDP, 1Ψ MEI 0 78900 (MEIC), Malaise in small wash.

Published as part of Hauser, Martin & Webb, Donald W., 2007, A revision of the new world stiletto fly genus Ataenogera Kröber (Diptera: Therevidae: Phycinae) with the description of two new species, pp. 41-67 in Zootaxa 1530 on pages 49-51, DOI: 10.5281/zenodo.177666