Odontacolus

Female. Tiny to small wasps, 1.01–2.38 mm in length; body slightly elongate, generally moderately slight in form. Head. In anterior view varying in shape from suboval or subtriangular, to elongate and broad in buccal region. Frons smooth or sculptured, median area often defined by difference in sculpture compared to surrounding face, central keel present and often reaching almost to medial ocellus, sometimes virtually absent. Compound eyes large though appearing smaller in species with elongate buccal region, usually setose though sometimes setae tiny and eyes appearing glabrous. Mandibles with three teeth, normally subequal in size, sometimes with middle tooth slightly longer or lower tooth slightly shorter. Head in lateral view rather narrow, tapering to mouth, particularly in species with elongate malar region. Head in dorsal view curved around anterior mesosoma. Occiput well exposed. Ocelli usually large, touching or close to orbital margin. Occipital carina complete dorsally, sometimes faint because of surrounding sculpture. Antenna 7-segmented, clava large and appearing unsegmented or with distinct suture lines so that clava comprises 4 segments. Mesosoma. Mesoscutum wider than long, usually flat or virtually so, sometimes dorsally convex. Notauli usually present as distinct grooves reaching no more than about half way to anterior margin of mesoscutum, sometimes virtually absent or hidden by coarse longitudinal sculpture. Mesoscutellum either flat or transverse, with posterior margin usually straight medially, or dorsally convex and semicircular or oval in shape. Propodeum with pair of broad, elongate spines which are blunt or truncate apically and flank the T1 horn. Wings. Macropterous, never brachypterous. Fore wing narrow basally, broad in apical half, sometimes fore margin sinuate and surface of apical half convex (spoon-shaped) and molded to convex dorsal surface of metasoma (i.e. subelytriform). Fore wing venation with tubular submarginal (Sc+R) and stigmal veins (r-rs), marginal vien (C+R) very short, postmarginal vein (R1) very short or absent; in Odontacolus veniprivus species group venation lacking except for incomplete submarginal vein, with pronounced infuscate patch at position of marginal (C+R) and stigmal veins (r-rs). Fore wing color varying from hyaline to having dark infuscate bands. Metasoma in dorsal view subpedunculate. T1 square or longitudinally slightly longer than wide (rarely more transverse), with parallel or slightly curved lateral margins. Metasoma widest in posterior half; in lateral view dorsal surface slightly to strongly convex. T1 with large, laterally compressed hornlike process (i.e. ellipsoidal in cross-section) which reaches to level of posterior mesocutellum or higher. T3 the largest tergite, slightly longer than T2, sometimes subequal in length with T2. Ovipositor at least 1.5× length of metasoma, with shaft curled back on itself within rounded head of the T1 horn. Gonoplacs elongate, approximately 0.75× length of metasoma. Male. Antenna short, 11-segmented, often appearing to be 9- or 10-segmented as distal antenomeres are closely joined, distal antenna becoming progressively broader so as to be subclavate. Metasomal horn absent, but anterior part of T1 inflected upwards.

Odontacolus is clearly more widespread than previously thought and, in the Old World, is found throughout Africa south of the Sahara, the Middle East (Odontacolus veniprivus group only; see Valerio et al. 2010), India, Sri Lanka, Nepal, south-east Asia (with one species extending north into China), and Australasia extending east in the Pacific to Fiji (Fig. 4, link to distribution map30). Australasia is the most species rich region (19 spp., four of which are endemic to Fiji), followed by India/south-east Asia (14 spp.) and Africa/Madagascar (11 spp.), the remainder of species have a broader distributions across regions.