Australachalcus setosus, 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 : 65-68

AUSTRALACHALCUS SETOSUS SP. NOV. ( FIG. 25 )

Male. Rather small, slender species. Head. Face pale brown, dusted, slightly wider than ocellus. Frons dark brown. Occiput convex ventrally, distinctly concave dorsally, dark brown, shining. Palp small (1/5 of eye), ovoid, whitish. Antenna with scape and pedicel mainly reddish yellow; scape distinctly infuscated dorsally and pedicel with narrow dark apical rim; first flagellomere mainly brown, elongate triangular, 2.2¥ as long as deep and 1.9¥ as long as scape and pedicel combined. Arista 0.7¥ as long as first three antennal joints, distinctly subapical, practically bare ( Fig. 25C ).

Thorax. Mesonotum and scutellum brown with yellowish dusting; humeri, notopleural areas and lateral parts of scutellum yellowish. Pleura reddish brown. Postnotum contrasting yellowish with rather strong black frontolateral triangle. Metapleura entirely brown. 6–7 ac, more than 1.5¥ as long as distance between rows. One small sutural bristle present, but without additional bristles.

Abdomen with tergites entirely brown, yellowish to greyish on 1st till 3rd laterally; with strong marginal bristles. Sternites greyish brown. Genital capsule dark brown, moderately developed, with dark aedeagus visible through posterior face. Hypopygium with simple hypandrium with raised apical rim; aedeagus dark, extremely thin and straight; epandrial setae inserted at base of epandrial lobe; midventral bristle of surstylus with apical flag; VEP and DEP evident; postgonites slender, slightly darkened on apex; cercus moderately developed, club-shaped ( Fig. 25E ).

Wing. Halter infuscated. Wing slightly infuscated, with R 4+5 hardly curved, R 4+5 and M 1+2 parallel. Proximal section of vein CuA 1 1.3¥ as long as apical section; CuAx ratio 2.5. Wing length 2.3–3.0 mm (n = 9) ( Fig. 25D ).

Legs including coxae whitish yellow, with femur II slightly infuscated and femur III infuscated on dorsal half. Femur I with erect ventral bristle at basal 1/9, 0.7¥ as long as femur is deep, basad of row of strong erect av bristles, decreasing in length towards apex; with three small erect pv bristles at extreme base and some inclined small pv bristles at apex; with one small av and two pv preapical bristles ( Fig. 25A ). Femur II with one row of erect av bristles, weakest at middle, only basal bristle as long as femur is deep, and one row of very strong erect pv bristles, decreasing in length towards apex; 4–5 basal pv bristles 1.4¥ as long as femur is deep; with one strong ad and one small av preapical bristles ( Fig. 25B ). Femur III with one rather weak ad, inserted in lower 1/3, and one strong av preapical bristle. Tibia I without dorsal bristles; tibia II with two small (1/11 of tibial length) ad and one small pd bristles, basal bristles forming ad-pd couple at basal 1/3; with ventral rows of indistinct slightly erect small spines. Tibia III brownish, slightly dilated at apex, with three very small ad, three very small pd bristles and 2–3 indistinct ventral setae. Tarsus I and II whitish yellow with 5th tarsomere dark; tarsus III entirely brownish. First tarsomere of leg III 0.8¥ as long as 2nd tarsomere. Body length 2.1–2.6 mm (n = 9).

Female. As in male, except for the following: face wider, about 2¥ as wide as ocellus. Palp 1/5 – 1/4 of eye, pale yellow with dark apical margin. Antenna with scape and pedicel pale yellow, infuscated dorsally; 1st flagellomere with basal half yellow, rounded triangular, 1.2¥ as long as deep and 1.3¥ as long as scape and pedicel combined; arista 1.5¥ as long as first three joints of antenna. Thorax pale brown. Abdomen with six pubescent segments; tergites brown with 1st and 2nd brownish yellow; anterior sternites brownish yellow, posterior ones pale brownish; 8th segment conical, with eight setae instead of dornen; cerci small. Tibia III with 2–3 ad and 3–4 pd bristles. Body length 2.2–2.8 mm, wing length 2.2–2.9 mm (n = 7).

Etymology. Refers to the strong av and pv bristles on femur II in this species.

Holotype. 1♂, CHILE: Region del Bernardo O’Higgins, Bosque de los Conservadores Graneros , 1100 m, 1–4.iii.1962 (L. Peña) ( CNC; D).

Paratypes. CHILE: Region de Valparaiso, Prov. Quillota: 10♂, 39♀, Palma de Ocoa, Parque Nacional Campanas , hillside draw, 32∞93¢24S 71∞07¢81W, 215 m, 21.xi-6.xii.1997 ; 12♂, 75♀, 6–20.xii.1997; 54♀, 20.xii.1997 – 10.i.1998; 5♂, 5♀, 10–31.i.1998; 8♂, 10♀, 31.i-14.ii.1998; 1♂, 14.ii-7.iii.1998, all MT ( Barria & Irwin) ( INHS; W); Prov. San Felipe de Aconcagua: 3♂, Aconcagua, Valle Los Piuquenes , 7– 12.ii.1964 (hypopygium and wing of 1♂ mounted; head of 1♂ lacking) ; Region del Maule, Prov. Curicó: 1♂, Curicó , El Coigual, 20–26.i.1964 (antenna, leg I and II, and hypopygium mounted) (all L. Peña) ( CNC; D) ; Region metropolitana de Santiago, Prov . Santiago: 1♂, 1♀, Queb La Plata , 5 km W. La Rinconada de Maipu, cyn. bottom, 400 m, 24.xi-7.xii.1997 , MT ( Barria & Irwin ) ( INHS; W) .

AUSTRALACHALCUS VARIABILIS SP. NOV.

( FIGS 26 , 27 )

Male. Rather small, slender species. Head. Face pale brown, moderately dusted, 1.5¥ as wide as ocellus. Frons dark brown. Occiput convex ventrally, distinctly concave dorsally, dark brown, shining. Palp small (1/6 of eye), circular, dark brown. Antenna mainly dark with scape and pedicel usually largely dark but sometimes almost entirely yellow (see Fig. 26C ); first flagellomere brown with basal 1/4 yellow, elongate triangular, 2.1¥ as long as deep and 1.9¥ as long as scape and pedicel combined. Arista 0.8¥ as long as first three joints of antenna, distinctly subapical, practically bare ( Fig. 26C ).

Thorax. Mesonotum and scutellum yellowish brown, with dusted lines along ac and dc. Pleura and postnotum brown, latter with very large black frontolateral triangle and narrow ventral black margin. Metapleura entirely pale brown. Seven ac, 1.5¥ as long as distance between rows. One minute sutural bristle present.

Abdomen with 2nd and 3rd abdominal tergites translucent whitish yellow, darker from apical half of 3rd to blackish brown on tergites 4–6; with strong marginal bristles and faint green reflection; 6th tergite half as long as 5th. Tergites with 1st to 3rd segment translucent brownish, darker from 4th onwards. Genital capsule moderately developed, blackish brown. Hypopygium with pseudo-spined hypandrium; aedeagus dark, very long and rather straight; midventral bristle of surstylus with apical flag; VEP evident; DEP not evident; postgonites slender and pale; cercus rather small, bean-shaped with strong marginal bristles ( Figs 26D , 27 ).

Wing. Halter and wing slightly infuscated, latter with R 4+5 curved, R 4+5 and M 1+2 slightly diverging towards wing apex. Proximal section of vein CuA 1 1.5¥ as long as apical section; CuAx ratio 2.1. Wing length 2.3– 2.7 mm (n = 5) ( Fig. 26B ).

Legs whitish yellow with darker tarsi. Coxa II and III reddish yellow. Femur I without erect ventral bristle and with two moderately strong pv preapical bristles. Femur II with one row of inclined av setae, weakest at middle, only basal bristle as long as femur is deep, and one row of very strong erect pv bristles, decreasing in length towards apex; basal pv bristle 1.7¥ as long as femur is deep; with one strong ad, one small av and one pv preapical bristles ( Fig. 26A ). Femur III distinctly infuscated on dorsal half with one rather weak ad, inserted in lower 1/3, and one strong av preapical bristle. Tibia I without dorsal bristles. Tibia II slightly dilated apically with one very small (1/12 of tibial length) ad and one very small pd bristles, basal bristles forming ad-pd couple at basal 1/3; with one ventral row of rather erect short spines on apical half; tibia III dilated towards apex, with two very small ad, three very small pd and four ventral setae. Tarsus I with 1st tarsomere yellow, 2nd to 4th darker yellow and 5th dark; tarsus II dark yellow with apical half of 5th tarsomere dark; tarsus III entirely brownish yellow. First tarsomere of leg III 0.8¥ as long as 2nd tarsomere. Body length 2.1 mm.

Female. Unknown.

Etymology. Refers to the variable colour of body and antenna in this species.

Holotype. 1♂, CHILE: Region de la Araucania, Prov. Malleco, Rio Blanco , 1100–2000 m, ii.1964 (L. Peña) ( CNC; D).

Paratypes. CHILE: Region de la Araucania, Prov. Malleco: 2♂, Rio Blanco , 1100–2000 m, ii.1964 (hypopygium of 1♂ mounted) ; Region del Maule, Prov. Curicó: 1♂, Curicó, Estero La Jaula ( Nothofagus ), i.1964 (wing and hypopygium mounted) ; Region metropolitana de Santiago, Prov. Santiago: 1♂, Cerro el Roble , 28–31.xii.1963 (wing, leg II, antenna & hypopygium mounted) (all L. Peña) ( CNC; D) .

Figures

Figure 25. Australachalcus setosus sp. nov. (male). A, femur I; B, femur II; C, antenna; D, wing; E, hypopygium.

Figure 26. Australachalcus variabilis sp. nov. (male). A, femur II; B, wing; C, antenna; D, hypopygium.

Figure 27. Australachalcus variabilis sp. nov. (male). Hypopygial appendages. A, aedeagus; B, hypandrium, ventral view; C, epandrial lobe; D, ventral process of epandrium; E, epandrial lobe (top) and surstylus (bottom); F, cercus.