Aprostocetus Westwood

Aprostocetus is the largest of the tetrastichine genera and it is known from all geographical realms. Species attack a wide variety of hosts, but hosts are often insects inhabiting a variety of plant galls, including Diptera, Hymenoptera, Coleoptera, Coccoidea and even eriophyid mites and nematodes (Graham 1987; La Salle 1994).

Generic keys that distinguish Aprostocetus from other tetrastichine genera are available for Australasia (Bouček 1988), North America (LaSalle 1994; Schauff et al. 1997), Europe (Graham 1987, 1991) and India (Narendran 2007). Diagnostic characters include: propodeal spiracle partially covered by a raised lobe or flap on the callus, one of the cercal setae distinctly longer than remaining setae and sinuate or curved, submarginal vein generally with 3 or more dorsal setae, malar sulcus straight or only slightly curved. Keys to species of Aprostocetus are known only for Europe (Graham 1987) and India (Narendran 2007).