Ariasina adusta Heydon, n. sp.

(Figs 7, 9, 10, 11, 12)

Diagnosis. Individuals of Ar. adusta are of medium size (body length around 3 mm) with the microsetae of the body brown. The head and mesosoma are dark brown to black. The female antenna has the flagellum clubbed, with only the basal flagellar segments appearing elongate, and with the length of the pedicel plus the flagellum approximately equal to the head width. This species is highly unusual within the Pteromalidae in that the female and male antennae resemble each other so closely.

Description. Holotype, female (MNNC). Color. Body with head and mesosoma almost black (Fig. 7), gaster dark reddish brown. Antenna brown. Legs brown except hind coxae dark brown. Wings hyaline with veins pale brown. Setae of body brown.

Sculpture. Metapleuron almost smooth; propodeum nearly smooth, with only a single submedian carinula laterad of median carina.

Structure. Body length 2.6 mm. Head width 1.3× height (43:33) (Fig. 12), 1.9× length (43:23); eye height 1.1× length (20:18.5), 1.5× malar distance (20:13), length 4.6× temple length (18.5:4); ratio of MOD, OOL, POL, LOL as 3:4:11:6. Antenna (Fig. 10) with length of pedicel plus flagellum 1.0× head width (45:43); scape not nearly reaching median ocellus, slightly flattened but not expanded, anterior edge rounded, nearly straight; flagellum clubbed; relative lengths of scape, pedicel, A1–2, F1-6, club as 18:7.5:2.0:5.5:3.5:3.5:3.0:3.0:3.0:2.5:8.5; A1 length about 1× width; widths of F1, F6, club as 3.0:4.0:6.0; F1–2 appearing elongate, F3–4 more quadrate, F5–6 transverse. Mesosomal length 2.0× width (72:36); propodeum smoothly arched from side to side; dorsal microsetae relatively dense, reclinate. Fore wing length 2.9× width (90:39); relative lengths of submarginal, marginal, postmarginal, and stigmal veins as 54:26:13:25. Gaster ovate acuminate; length 2.3× width (90:39), 1.0× combined length of head and mesosoma (90:90); hypopygium extending just over 1/3 length of gaster.

Allotype male (UCDC) similar to holotype except antenna (Fig. 9) more parallel-sided, though overall similar in appearance to female antenna; pedicel plus flagellum 1.0× head width (44:43), relative lengths of scape, pedicel, A1–2, F1-6, club as 18:7.0:2.0:5.0:4.5:4.0:3.5:3.5:3.5:3.5:9.5; clavate, widths of F1:F6: club as 2.5:4.0:5.5.

Type material. Holotype, allotype and 5 paratype females and 4 paratype males (EMEC, UCDC) were collected in CHILE: IX REGIÓN, Flor del Lago Ranch, 11km ne. Villarica, 39˚12.5’S 72˚ 08.1’W (290m), on 12.VIII.2001 by E. Arias canopy fogging Nothofagus obliqua Roble. Nine other paratypes were collected as follows (UCDC, MLPA, MNNC): CHILE. IX REGIÓN, polo field at Flor del Lago Ranch near Villarica, 39˚12.3’S 72˚8.3’W, 280 m, 13.XII.2001, canopy fogging WT Nothofagus obliqua Roble (Arias 18), 1 ♀, 7 ♂; polo field at Flor del Lago Ranch near Villarica, 39˚13’S 72˚08’W, 313 m, 15.XII.2001, canopy fogging WT Nothofagus obliqua Roble (Arias 18), 1 ♀.

Etymology. The species name is from the Latin word adustus, meaning brown or tanned by the sun.

Biology. This species has been taken repeatedly by fogging off of Nothofagus obliqua.