Chaetocnemistoptera lobata Ament, 2014, sp. nov.

Chaetocnemistoptera lobata, sp. nov.

(Figs 5, 11, 26, 33–34, 51–54)

Diagnosis (male). Hind femur with ventral bare lobe near base (Figs. 33–34).

Material examined. Holotype ♂, BOLIVIA: La Paz: 40 km N Caranavi: Cumbre Alto Beni. 15.83ºS 67.56ºW, 7–15.iv.2004, Malaise trap, 1600m, B. Brown & E. Zumbado col. (CFBC). Paratypes: COLOMBIA: 1♂, Amazonas: PNN Amacayacu Matamata, 3.82ºS 70.26ºW, 25.viii-3.ix.2000, Malaise trap, 150m, D. Chota col. (LACM); 1♂, Vichada: PNN El Tuparro: Cerro Tomas, 5.35ºN 67.85ºW, 21–31.i.2001, Malaise trap, 140m, W. Villalba col. (LACM); 1♂, Vaupés: Est. Biol. Mosiro-Ijaura (Caparú) Antigua Cabina, 1.07ºN 69.52ºW, 18– 27.iii.2003, Malaise trap, 60m, J. Pinzón col. (LACM); ECUADOR: 1♂, Napo: Yasuni NP Puce Yasuni Research Stn, 0.67ºS 76.6ºW, 3–20.xi.1998, Malaise trap, T. Pape & B Viklund col. (LACM); 1♂, Sucumbios: Sacha Lodge, 0.5ºS 75.5ºW, 27.viii–10.ix.1994, Malaise trap, 270m, P. Hibbs col. (LACM); FRENCH GUIANA: 1♂, Regina: Kaw Mtn. Patawa, 4.55ºN 52.17ºW, i.2006, Malaise trap, 300m, J.A. Cerda col. (LACM); BRAZIL: 1♂, Amazonas: Manaus: PDBFF Res. 1301, 3.13ºS 60.02ºW, 30.x.1985, Malaise trap, B. Klein col. (LACM); 1♂, Amazonas: Manaus: PDBFF Res. Km 41, 10–12.xi.2004, Malaise trap, R. Querino col. (INPA); 1♂, Amazonas: Manaus: Reserva Ducke, Igarapé Bolívia, i.2003, Malaise trap, J. Vidal col. (INPA); PERU: 1♂, Madre de Dios: Pakitza, 11.94ºS 71.28ºW, 10.vi–6.vii.1993, pan trap, R. Cambra col. (LACM).

Description. Male. Body length, 1.7–2.6 mm. Head. Frons yellow in the ventral half, progressively brown in the dorsal half, pubescent, without median furrow. Ventral fronto-orbital setae close to the eye margin, ventral interfrontal setae about midway between eye margin and frons midline (Fig. 11). Flagellomere 1 light brown, pubescent, oval. Arista pre-apical, pubescent. Palpus yellowish-brown. Thorax. Scutum and pleural regions yellowish-brown (Fig. 5), scutellum brown, with median and posterior regions gray; anepisternum dorsally setulose. Legs yellowish-brown, hind femur brown at apex. Foretibia with one dorsal seta at basal quarter and anterodorsal row of strong setae. Midtibia with two basal transverse combs of setae, one anterodorsal and two posterodorsal setae and 2–3 small posterodorsal setae between the two large ones. Hind femur swollen (height/ length ratio: 0.47), with ventral lobe near base (Figs. 33–34). Hind tibia with one anterodorsal and 4–6 posterodorsal setae and 12 transversal combs of setae. Wing. (Fig. 26) Costa 0.4 of the wing length, other characteristics as described for the genus. Halter yellowish-brown. Abdomen. Tergites dark brown. T1–T5 with yellow median and posterior regions. Hypopygium light yellow (Figs. 51–54). Left epandrial process large, ventrally concave, with two apical lobes and subepandrial apically setose process. Hypandrium bilobed, laterally microtrichose. Hypoproct with two setae.

Female. Unknown.

Geographic distribution. Amazonian South America (Fig. 72).

Etymology. The specific epithet lobata refers to the hind femur lobe of this species and is derived from the Greek root lobus (lobe).

Comments. Some of the paratypes have the scutum posterior margin brown, differing from the holotype. Other variation observed in some specimens is the presence of a rounded projection of the right epandrial margin. Neither of these variations was considered significant as indicative of a different species.