Stylops melittae

Stylops melittae primarily parasitizes species of sand bees that use the blossoms of multiple plants (that is, those that are polylectic); sand bee species specialized for blossoms of a single or few plant species, are more rarely affected. This distribution regarding host specificity would not be expected.

Stylops melittae has a markedly variable appearance. The proportions of the cephalothorax of the female have a great range of variability and consequently at times sequences of apparently host-specific species have been described, that have since been subsumed under single species.

Female sand bees become parasitized far more often than males.

Stylops-parasitized female sand bees are sterile and express themselves in behavior and appearance rather like their male counterparts of the species. The pollen gathering apparatus is reduced, the abdomen is flatter, and also the coloration is reminiscent of male individuals. Furthermore the stylops-parasitized female bees leave the maternal nest a few days earlier than do uninfested female individuals, similarly as do healthy male individuals. The earlier flight of the infested females gives the parasite more time for the development of the primary larvae. Stylops-parasitized females are no longer active after they have dug out their nest, while healthy females then fly out to provide for their offspring.

The less often infested male sand bees are by their appearance less affected, but are rather reminiscent of the female animals.

William Kirby was responsible for classifying the Strepsiptera as a separate order of insects. On the foundation of the Entomological Society of London in 1833 William Kirby was made Honorary Life President and Stylops melittae (then known as Stylops kirbyi) was adopted as the society’s symbol. The seal was first used for a letter by the society to William Kirby, which was signed by the president and thirty members in 1836 to thank him for presenting the society with a cabinet containing his entire insect collection. The society's badge has remained almost unchanged since its first use.^[6][7]