Austrosystasinae incertae sedis new placement

Austrosystasinae Bouček, 1988. Type genus: Austrosystasis Girault, 1924.

Diagnosis.

Antenna with 12 flagellomeres, including a small 4th clavomere. Eyes slightly linearly divergent ventrally. Clypeus with transverse subapical groove. Labrum hidden, flexible, with marginal setae in a row (Fig. 60). Subforaminal bridge with postgena separated by lower tentorial bridge, with a short apparent postgenal bridge immediately dorsal to the hypostoma. Mesoscutellum with frenum indicated laterally, with axillular sulcus. Mesopleural area without an expanded acropleuron; mesepimeron not extending over anterior margin of metapleuron (Fig. 61). All legs with 5 tarsomeres; protibial spur stout and curved; basitarsal comb longitudinal. Metasoma with syntergum, therefore without epipygium, rigidly convex.

Discussion.

Austrosystasis atricorpus Girault, the sole species in this subfamily, has not been sequenced, and its place is uncertain given our incomplete knowledge of its morphology. It appears to be a member of the Gall Clade, and it is an associate of galls on Elaeocarpus ( Elaeocarpaceae) in Australia. It has rough surface sculpture (Fig. 61) that causes it to resemble Eurytomidae (especially Rileyinae), although it has a shorter pronotum. Otherwise, it resembles Melanosomellidae, differing in having a distinct and complete axillular sulcus and distinctive sculpture on the axillula. It also resembles Ormyridae in overall body shape, but this could be attributed to gall association in both taxa. The differing sculpture of the axillula and the posterior surface of the head separate Austrosystasinae from Ormyridae . Given that A. atricorpus would complicate the diagnosis of whatever family it could be transferred to, the genus is dealt with here as incertae sedis in Chalcidoidea .