Australachalcus albipalpus, (PARENT), 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 : 51-53

AUSTRALACHALCUS ALBIPALPUS (PARENT)

COMB. NOV. ( FIGS 13 , 14 )

Achalcus albipalpus Parent, 1931: 20

Male. Large, slender species. Head. Face greyish brown, about as wide as ocellus. Frons dark brown. Occiput dark brown, convex with slightly concave area dorsally. Palp very large (2/5 of eye), ovoid, conspicuously silvery white with black setae on disc and short white marginal fringe. Proboscis distinctly protruding. Antenna largely dark with scape yellowish on ventral half at apex; pedicel yellow, infuscated on dorsal half; first flagellomere dark, paler at extreme base, elongate triangular, 2¥ as long as deep and 1.6¥ as long as scape and pedicel combined. Arista 0.9¥ as long as first three joints of antenna, apparently subapical, pubescent ( Fig. 13C ).

Thorax. Mesonotum and scutellum yellowish brown with dark areas anteriorly and between dc, extending upon prescutellar depression. Pleura brown. Postnotum yellowish with very broad black frontolateral margin. Metapleura with lower part brownish yellow and upper part brown. Six ac, 1.5¥ as long as distance between rows. Sutural bristle absent. One small bristle present between ps and 2nd dc.

Abdomen with five pubescent segments, 6th segment largely enclosed by 5th segment. Abdominal tergites brown to dark brown, 2nd with lateral yellowish spots on lower half. Sternites dark brown, 5th divided in two triangular parts by caudal incision. Genital capsule brownish yellow to yellow, well developed. Hypopygium with apicoventrally spined hypandrium; aedeagus pale, straight and slender; ventral bristle of surstylus with apical flag; VEP and DEP evident; postgonites large and dark; cercus large, elongate ovoid, pale yellow with strong external and small internal bristles ( Fig. 13D ).

Wing. Halter pale. Wing slightly infuscated, with R 4+5 distinctly curved, diverging from M 1+2 at apex. Proximal section of vein CuA 1 3.6¥ as long as apical section; CuAx ratio 0.9. Wing length 3.6–3.9 mm (n = 7) ( Fig. 13A ).

Legs mainly yellow with coxa I pale yellow and coxa II and III brown, former only yellow on anterior face. Femur I and II slightly infuscated, femur III distinctly infuscated on dorsal half and on knee. Femur I with erect ventral bristle, almost as long as femur is deep, basad of row of 6–7 very strong and erect av bristles, decreasing in length towards apex ( Fig. 14 ); with 1–2 pv preapical bristles ( Fig. 14 ). Femur II with one rather weak ad, one av and one strong pv preapical bristles. Femur III with one thin but long ad, inserted in lower 1/3 and one strong av preapical bristles. Tibiae pale yellow; tibia I without dorsal bristles, with dense short dorsal and ventral pubescence as long as tibial depth; tibia II with two weak ad and one stronger pd bristles; basal bristles not forming ad-pd couple; tibia III with three ad and three pd bristles, and about nine distinct ventral setae. Tarsus I pale yellow, tarsus II and III dark yellow. First tarsomere of leg III 0.8¥ as long as 2nd tarsomere. Body length 2.6– 3.0 mm (n = 7).

Female. As in male, except for the following: face dark brown, 2¥ as wide as ocellus. Palp large (1/3 of eye), ovoid triangular, dark brown with yellowish spot at extreme inner basis. Antenna with scape and pedicel pale yellow with dorsal half and 1/3 resp. distinctly infuscated; 1st flagellomere dark with basal 1/3 pale, rounded triangular, 1.3¥ as long as deep and 1.3¥ as long as scape and pedicel combined; arista 1.4¥ as long as first three joints of antenna ( Fig. 13B ). Coxa I with basis infuscated, coxa III reddish yellow. Abdomen with six pubescent segments; tergites brownish black and sternites dark brown, dusted greyish. Body length 2.7–3.7 mm, wing length 3.9–4.5 mm (n = 16).

Syntype. 1♂, CHILE: Region de los Lagos, Prov. Valdivia, Corral , 7.ix.1902 (Schnuse) ( SMTD; D, hypopygium mounted), examined (hypopygium mounted but unrecognizable by overclearing). Labels: ‘Chile 7.IX.02 Corral’ (green label)/‘Typus Achalcus albipalpus Par. ’ (red label) /‘ Syntypus des. U. Kallweit, 1993’ (red orange label)/ ‘ Achalcus albipalpus O. Par- ent’ (white folded label)/‘Staatl. Museum für Tierkunde, Dresden’ (white label).

Material examined. CHILE: Region Aisen, Prov . Aisén: 2♂, 5♀, Puerto Cisnes 72∞40¢W 44∞45¢S, 1– 15.ii.1961; 1♂, 1♀, 15–28.ii.1961; 3♂, 4♀, 16– 28.ii.1961 ; Region de la Araucania, Prov. Malleco: 1♀, Rio Blanco, 1100– 2000 m, ii.1964 (all L. Peña) (POL- LET, CNC; D); 1♀, Rio Manzanares , 2.i.1966 (Flint & Cekalovic) ( USNM; D); Rio Region de los Lagos, Prov. Chiloé: 1♀, Isla Chiloé, Dalcahue , 1–8.ii.1962; 1♂, 2♀, 17–22.i.1962; Prov. Llanquihue : 2♀, Ensenada , Nothofagus forest, 13–15.i.1962 (all L. Peña) ( CNC; D); Prov. Osorno: 1♂, Lago Puyehue, 80 km E. of Osorno (tree trunk), 17–18.i.1997, ST (Bickel) ( CNC; W, hypopygium mounted) ; Region del Biobio, Prov . Arauco: 1♀ , Arauco, Pichinahuel, Cord. Nahuelbuta , 28.iii.1955 (L. Peña) ( CNC; D) .

Figures

Figure 13. Australachalcus albipalpus (Parent) (male, unless mentioned otherwise). A, wing; B, female antenna; C, antenna; D, hypopygium; E, epandrial setae at base of epandrial lobe.

Figure 14. Australachalcus albipalpus (Parent) (male). Coxa and femur I.