''Stylops melittae'' is a species of the order

Strepsiptera The Strepsiptera are an order of insects with eleven extant families that include about 600 described species. They are endoparasites in other insects, such as bees, wasps, leafhoppers, silverfish, and cockroaches. Females of most species never ...

of flying insects, that

parasitize Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

various species of sand bees (''Andrena'').Bleidorn, Christoph; Feitz, Fernand; Schneider, Nico; Venne, Christian
''Zum Vorkommen von Stylops melittae Kirby, 1802 (Insecta, Strepsiptera) in Luxemburg''
Bull. Soc. Nat. luxemb. 105 (2004) p. 137–142

Biology

The female ''Stylops melittae'' gives birth to a large number of motile primary larvae, that are strewn upon blossoms. From there they can be delivered along with the

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

at the nest construction of the sand bees for which the species is specialized. In the nest construction the primary larvae penetrate into the host larvae and molt into exclusively

endoparasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

secondary larvae. These roam about feeding in the host, and after a few further moltings establish themselves in the abdomen, and with their anterior portion break through between two abdominal segments of the host's skin, where they pupate. The exit point lays mostly between the 4th and 5th, more rarely between the 3rd and 4th, abdominal segment. There are substantially more females (77–92%) than males (2–23%).Straka, J.; Rezkova, K.; Batelka, J.; Kratochvíl, L
''Early nest emergence of females parasitised by Strepsiptera in protandrous bees (Hymenoptera Andrenidae).''
Ethology Ecology & Evolution 23: 97–109, 2011Kuhlmann, M
''Nachweise mit Bienen und Wespen (Hymenoptera Aculeata) assoziierter Milben (Acari) und Fächerflügler (Strepsiptera)''
Linzer biol. Beitr. 30/1 69-80 31.7.1998 The females remain all their lives in this

puparium A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

where they will be visited by the males for the purpose of copulation. Therefore, the females release a

pheromone A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...

(3,5,9-trimethyldodecanal) produced by cephalothoracic gland and attract the males. ''Stylops melittae'' can emerge in two generations, but most emerge in just one generation, so that stylops-infested sand bees are encountered mostly just in the early months of the year March through May.

Influence on the host species

''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 The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...

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.

In science and culture

William Kirby was responsible for classifying the Strepsiptera as a separate

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

of insects. On the foundation of the

Entomological Society of London The Royal Entomological Society is devoted to the study of insects. Its aims are to disseminate information about insects and improving communication between entomologists. The society was founded in 1833 as 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. Royal Entomological Society ,
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References

{{Taxonbar, from=Q2359722 Strepsiptera Insects of Europe Taxa named by William Kirby (entomologist) Insects described in 1802 Parasites of bees Parasitic insects