Twisted wing parasites are an enigmatic group of insects due to their small size and unusual life history. They are most closely related to the beetles (Coleoptera), but lack elytra, the hard forewings found in beetles. Stylops ovinae is a parasite of an Andrenid bee. Immatures are streamlined and covered with hairs. Larvae are mobile and have functional legs. As seen in image (left) two long cerci extend from the tip of the abdomen. The role and function of these appendages are unknown. The larvae are at the extreme lower size range for insects, and many unique morphological changes occur that adapt them to a small size.
*Pieter Knauthe, Rolf G. Beutel, Thomas Hörnschemeyer & Hans Pohl. 2016. Serial block-face scanning electron microscopy sheds new light on the head anatomy of an extremely miniaturized insect larva (Strepsiptera). Arthropod Systematics and Phylogeny. 74(2): 107–126.