Insect Order Strepsiptera - stylops
These are small (1.5 to 4.0 mms long), rather unusual looking insects. They are 'endoparasites' (parasites that live inside the bodies of their hosts, as compared with ectoparasites which live on the outside) of solitary bees, solitary wasps and other aculeates as well as various true bugs. The female is mostly flightless and are degenerate in that she has no legs and a body that looks rather like a maggot. The males have only one pair of functional wings, and these are the hind wings, the forewings are greatly reduced to look and function like the halteres of flies. They are not that common and few people other than entomologists have or are likey to see them. Their common name of Stylops becomes an adjective when describing the hosts that are carrying them, hence an insect suffering from parasitism by 'Strepsiptera' is described as being 'stylopised'. There are about 370 species known throughout the world of which 17 appear in the UK.
Strepsiptera are small endoparasitic insects. The males are free living and have unusual 'flabellate' (with projecting flaps on one side) antennae, biting mouthparts and the fore wings reduced to small club-like appendages. The hind wings are relatively large and leathery with longitudinal but no cross veins. The abdomen is 10 segmented and the adeagus (the organ used to transfer sperm to the female) is on the 9th sternum. They have no cerci. The females, except in the Mengenillidae, are larviform (look like a larva) and lives entirely within the last larval skin within which she also pupated, inside the body of her host. The head and thorax are united to form a cephalothorax. She also has no antennae or eyes and very reduced mouthparts. In the Mengenillidae the females are free living and have legs eyes and antennae.