(Figs 21–28)

Diagnosis. Female (male unknown): head and mesosoma with conspicuous metallic reflections (Fig. 21); gena conspicuously depressed at mouth corner (Fig. 26); toruli closer to ventral margin of clypeus than to median ocellus (Fig. 22); basal two teeth of right mandible very short and close to each other (Fig. 25); notauli visible only in anterior third of mesoscutum (Fig. 23); marginal vein about 4× as long as broad (Fig. 28).

Austroterobia heydoni is easily recognizable by its very short marginal vein (Fig. 28), which is unique among the presently known species of Austroterobia.

Material examined. Type material. Holotype ♀ (deposited in UCD) [entire; on triangular card]. D. R. CONGO: ‘Dem. Rep. Congo, Bandundu: Wamba, Kikongo Mission, 4°15’S 17°10’E’, ’ 20.IV.2006, S. L. Heydon, S. E. Stevenson, forest Malaise’.

Description. Female. Body length: 1.2 mm.

Colour. Head and dorsal side of mesosoma brownish-black, with conspicuous greenish metallic reflections (Fig. 21); lateral side of mesosoma brown (Fig. 27). Gaster brown (Fig. 21). Eyes and ocelli pale reddish-grey (Figs 22, 23, 26). Antenna (Figs 21, 24) with scape yellowish; pedicel light brown dorsally, paler ventrally; flagellum light brown. Mandibles yellowish, teeth reddish-brown (Fig. 25). Fore and mid legs entirely yellowish; hind legs with femora yellowish-brown (Fig. 21). Wings hyaline, tegula and venation brown (Fig. 28). Body setation whitish, wing setation brown (Fig. 22, 23, 28).

Sculpture. Head and most of dorsal side of mesosoma coriaceous to alutaceous except for smooth lower part of clypeus (Figs 22, 26); malar depression with sculpture denser (Fig. 26); prepectus smooth (Fig. 27); mesopleuron mostly smooth except for finely reticulate lower mesepisternum and shallow femoral depression, with indication of a central pit (Fig. 27); metapleuron extremely finely alutaceous (Fig. 27); gaster smooth.

Structure. Head. Toruli closer to ventral margin of clypeus than to median ocellus (Fig. 22). Scape not reaching median ocellus (Fig. 21). Gena conspicuously depressed at mouth corner (Fig. 26), posterior margin finely carinate. Malar sulcus absent (Fig. 26). Eyes broad oval, inner margins not sinuate in middle and almost parallel in lower part (Fig. 22). Funicular segments not pedicellate (Fig. 24). Head width about 2.2× length (42:19) in dorsal view and 1.2× height (42:35) in frontal view. POL about 1.1× OOL (9:8). Eye height about 1.3× length (19:15), about 2.1× malar space (19:9), and about 1.3× scape length (19:15). Head width 1.2× length of pedicel plus flagellum (42:35). F1 width about 1.1× length (4.0:3.5); F5 width 1.5× length (4.5:3.0); clava length 2.2× width (11:5).

Mesosoma. Dorsally setose except for metanotum and median area of propodeum (Fig. 23); prepectus and metapleuron bare (Fig. 27); mesopleuron bare except for some setae on lower mesepisternum (Fig. 27). Pronotum barely visible in dorsal view. Notauli deep only in anterior third of mesoscutum (Fig. 23). Axillae wide apart, medially connected by slightly widened groove separating mesoscutum from mesoscutellum (Fig. 23). Posterior margin of mesoscutellum evenly curved. Fore wing (Fig. 28) with small speculum, otherwise completely setose; parastigma without hyaline break; marginal vein distinctly thickened. Mesosoma length about 1.1× width (40:35), width 1.4× height (35:25). Mesoscutum width about 2.3× length (35:15). Mesoscutellum length about 0.9× width (13:15). Fore wing length about twice width (85:43); MV length about 4× width (12:3); MV 0.85× SV (12:14); PV about 1.8× MV (22:12).

Gaster. Ovate, about equal to head plus mesosoma (Fig. 21); length about 1.6× width (55: 35).

Male. Unknown.

Distribution. Democratic Republic of Congo.

Biology. Unknown.

Remarks. Unfortunately, the propodeum of the holotype is mostly concealed by glue (Fig. 21), so nothing can be observed about its structure, except that its central area is apparently not setose. However, based on the observed structure of the propodeum in all of the other species of Austroterobia it is highly probable that it has a complete median carina and well developed plicae. A remarkable character of A. heydoni is the structure of the right mandible, where the two inner teeth are small and very close to each other, appearing as one double tooth (Fig. 25). The structure of the left mandible is characteristic for Austroterobia, while the right mandible structure together with the unusually short marginal vein may indicate a close relationship with Teasienna. However, the species does not have the other characters of Teasienna, so it is described in Austroterobia. Austroterobia heydoni is the only Afrotropical species of Austroterobia with incomplete notauli.

Etymology. Named in honour of Dr. Steve Heydon (UCD), the collector of the holotype, for his contribution to the systematics of Chalcidoidea.