Polyommatus

Polyommatus is a genus of butterflies in the family Lycaenidae, commonly known as blues. It belongs to the subfamily Polyommatinae and the tribe Polyommatini. The genus comprises a large number of species distributed across the Palearctic region, including Europe, Asia, and parts of Africa, with many localized and habitat-specific representatives.

Most males in Polyommatus species exhibit blue uppersides, while females are typically brown or orange-brown. The undersides are patterned with a network of lines and dark spot markings, often with white or light markings along the wing margins. Many species show hindwing tails, and wingspan typically ranges from about 15 to 30 millimeters. Individuals often display strong sexual dimorphism and species-specific variation in wing patterns, making field identification challenging.

Ecology and life history are characteristic of the group. Larvae usually feed on plants in the Fabaceae family, including clovers (Trifolium), birds-foot trefoils (Lotus), and medicks (Medicago). A notable feature of many Polyommatus species is myrmecophily: caterpillars or early instars are tended by ants, which protect them in exchange for sugary secretions. Adults sip nectar and have flight periods ranging from spring to late summer, with some species producing multiple generations per year depending on climate.

Taxonomy within Polyommatus has been dynamic, with molecular studies prompting reclassifications and transfers of species among related genera. Notable members include Polyommatus icarus (the common blue) and Polyommatus bellargus (the Adonis blue). The genus remains a focal point for studies on speciation, biogeography, and the ecological interactions of insects in grassland and open-habitat ecosystems.