Australachalcus robustus, Pollet, 2005, Pollet, 2005

Pollet, Marc, 2005, Systematic revision of Neotropical Achalcus and a related new genus (Diptera: Dolichopodidae, Achalcinae) with comments on their phylogeny, ecology and zoogeography, Zoological Journal of the Linnean Society 143 (1), pp. 27-73: 64-65

publication ID 10.1111/j.1096-3642.2004.00141.x

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scientific name

Australachalcus robustus



Male. Small, stout species. Head. Face dark brown, 1.5¥ as wide as ocellus. Frons dark brown. Occiput distinctly concave dorsally, dark brown. Palp small (1/6 of eye), ovoid circular, small, dark brown. Antenna almost entirely dark with pedicel reddish yellow on ventral half on inner face; first flagellomere rounded triangular with acute apex, 1.6¥ as long as wide and 1.6¥ as long as scape and pedicel combined. Arista as long as first three joints of antenna, distinctly subapical, with microscopic pubescence ( Fig. 24C View Figure 24 ).

Thorax including metapleura blackish brown with olive-green reflection; humeri with minute yellow spot. Pleura and postnotum dark brown, postnotum with black frontolateral margin. 5–6 very strong ac, more than 2¥ as long as distance between rows. One small sutural bristle present. About three small bristles present between ps, sutural and 1st and 2nd dc.

Abdomen blackish with olive-green reflection, genital capsule brown. Tergites with very strong marginal bristles; 6th tergite small, 5th sternite with caudal incision. Hypopygium with apicoventrally spined hypandrium; aedeagus with recurrent apical process; midventral bristle of surstylus with apical flag; VEP evident; DEP not evident; postgonites dark; cercus rather small, reversed triangular, with strong apical bristles and apical fringe ( Fig. 24B View Figure 24 ).

Wing. Halter pale. Wing very slightly darkened, with R 4+5 slightly curved; R 4+5 and M 1+2 almost parallel at wing apex. Proximal section of vein CuA 1 1.9¥ as long as apical section; CuAx ratio 1.6. Wing length 2.1 mm ( Fig. 24A View Figure 24 ).

Legs mainly dark to brownish yellow, femora distinctly infuscated dorsally. Coxae dark brown, only coxa I paler at extreme apex. Trochanters whitish yellow. Femur I brownish, darkened dorsally, with one very strong erect ventral bristle at basal 1/6, 1.5¥ as long as femur is deep, basad of 1–3 small, less erect av bristles on basal 1/3; with two strong pv preapical bristles ( Fig. 24D View Figure 24 ). Femur II dark yellow, distinctly darkened on dorsal half; with one row of 5–6 very strong (basal bristles 1.5¥ femur depth) erect av bristles in basal half, then decreasing in length towards apex; with one strong ad and one small pv preapical bristles ( Fig. 24E View Figure 24 ). Femur III pale yellow, distinctly infuscated on dorsal half, with one moderately strong ad, inserted in lower 1/3, and one very strong av preapical bristles. Tibia I pale yellow, without dorsal bristles and with dense dorsal and ventral pubescence; tibia II yellow with one very strong (more than 1/5 of tibial length) ad and one very strong pd bristles, basal bristles forming ad-pd couple at basal 1/4; tibia III brownish, gradually swollen towards apex, with one small ad and two small pd bristles; with dense pd and ventral pubescence. Tarsus I dark yellow with 4th and 5th tarsomeres darker; tarsus II darkened with 5th tarsomere dark; tarsus III entirely dark brown. First tarsomere of leg III 0.9¥ as long as 2nd tarsomere. Body length 1.7 mm.

Female. Unknown.

Etymology. Refers to the robust appearance (stout, compact body shape, relatively short legs) of this species.

Holotype. 1♂, CHILE: Region de los Lagos, Prov. Chiloé, Isla Chiloé, Dalcahue , 17–22.i.1962 (L. Peña) ( CNC; D, hypopygium mounted).  


Canadian National Collection of Insects, Arachnids, and Nematodes