Megascogaster Baker , 1926

Kittel, Rebecca N., 2014, Revision of Megascogaster (Hymenoptera, Braconidae, Cheloninae), with a new species from Sulawesi, Indonesia, Zootaxa 3860 (4), pp. 371-378 : 372

Genus Megascogaster Baker, 1926

Megascogaster Baker, 1926: 487 . Type species: Megascogaster elongata Baker , by original designation (NMNH). Megascogaster: Shenefelt 1973: 878 , Yu et al. 2012, Zettel 1990c: 189.

Diagnosis. Large chelonines, more than 5.5 mm long; eyes glabrous, oval, and protruding; clypeus with two teeth; hypostomal carina reaching occipital carina; malar suture absent; 28–33 antennomeres; frons deeply invaginated; ocelli forming an equilateral triangle; occipital carina complete or dorsally interrupted; notauli present and scrobiculate; scutellar sulcus present and areolate; propodeal tubercules present or absent; vein CUIb present; SR-1 curved; vein r-m not sclerotized; 2-SR+M antefurcal; 3-SR postfurcal; cua short, postfurcal; 2-R1 present; 1-SR+M vein from parastigma; pterostigma long and elliptical; carapace without transverse sutures, slender, elongate, acute posteriorly.

Comments. The relationship of Megascogaster with Ascogaster has been discussed several times ( Baltazar, 1962, 1966; Zettel, 1990c; Tang & Marsh, 1994) as both genera lack sutures on the carapace and have 1+SR+M vein present in the fore wing. However, they differ a great deal in other characteristics. The ratio of the length of metasoma to the length of mesosoma plus head (longer than head and mesosoma together) has been the preferred character used by several authors to distinguish the two genera ( Baltazar, 1962, 1966; Zettel, 1990c). However, there are still undescribed Ascogaster species with this uncommon ratio (unpublished observations of Australian Ascogaster ). The following characters provide a more definitive diagnosis that can be used to separate Megascogaster from Ascogaster : the hypostomal carina extending to occipital carina (not the case in Ascogaster ), the elliptical shape of the pterostigma (more rounded in Ascogaster ), fore wing vein 1-cu1 being short postfurcal to cua (longer in Ascogaster ), and the long and slender shape of the carapace.

Distribution. As discussed by Kittel and Austin (2014) the genus occurs in the Oriental region (type locality the Philippines) and now also includes the new species described below from Sulawesi, Indonesia on the southern side of Wallace’s Line in the Australasian region. A third, as yet undescribed species has also been recorded from Vietnam (pers. com. Cees van Achterberg), indicating much broader distribution of the genus though Southeast Asia.

Biology. The hosts of Megascogaster are unknown.