Overview
Scelionids
parasitise
the eggs of Araneae (spiders) and most major insect groups including Orthoptera (grasshoppers and crickets), Mantodea (preying mantids), Embioptera (web spinners), Hemiptera (bugs), Coleoptera (beetles) and Lepidoptera (moths and butterflies). They occur in all habitats and often in large numbers, particularly in cryptobiotic niches (concealed or secluded situations, such as in leaf litter). Scelionids that occur in leaf-litter are often brachypterous (reduced winged) or wingless, while others (e.g
. Ceratobaeus
,
Odontacolus
,
Probaryconus
) have a horn-like structure on the first metasomal tergite that provides a recess for the elongate hypodermic-like ovipositor.
Galloway and Austin (1984) provide a key to genera of the largest subfamily Scelioninae, although this is now somewhat out of date, and Austin
et al
. (2005) provide an extensive review of the systematics and biology of the group. Dangerfield
et al
. (2001) revised the Australian species of
Scelio
, a genus that parasitises grasshopper and locust eggs.
Description
Members of this family are all endoparasitic in the eggs of insects and spiders. They are minute to small wasps (0.5 2.5 mm, rarely up to 7 mm) that have reduced wing venation but usually with some veins running along or near the anterior margin of the wings. The antennae are geniculate (elbowed), inserted close together just above the mouth and clavate in females (as in
Platygastridae)
, and the metasoma slightly or strongly flattened and normally has a sharp lateral margin.
Further information about the Scelionidae can be found in Austin & Field 1997, Austin, Johnson & Dowton 2005, Dangerfield, Austin & Baker 2001, Galloway & Austin 1984, Masner 1993 and Naumann 1991.