Overview
The distribution is cosmopolitan.
Stylops
, the largest genus in the family, is restricted to the Holarctic is parasitic on Andrenidae Region and includes parasites of Andrenidae. The Australian fauna contains more than 65 species in the genera
Hylecthrus
,
Halictoxenos
,
Xenos
,
Pseudoxenos
,
Paragioxenos
, and two undescribed genera, one associated with the wasp genera
Bembix
and
Bembicinus
, and the other with the bee genus
Paracolletes
.
Pseudoxenos
, which contains parasites of sphecine and eumenine wasps, is a dominant genus in Australia.
Xenos
, a dominant genus in the Neotropical Region but poorly represented in Australia, contains parasites of social wasps (Kathirithamby in press).
Description
This is the largest family of Strepsiptera and has been divided by Kinzelbach (1978) into the subfamilies
Xeninae
,
Paraxeninae
and
Stylopinae
, which parasitise Vespidae, Sphecoidea and Apoidea, respectively. The males are distinguished by the 4-segmented tarsi, 4- or 6-segmented antennae, metacoxae and aedeagus. The females have a flattened cephalothorax with 2-5 genital apertures.