What Bug Is That? The guide to Australian insect families.

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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).


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.

  • A close up of Stylops pacifica , female

  • A Stylops pacifica , female, parasitising a bee ( Andrena suavis )

  • Hylecthrus sp., adult male