Phengaris nausithous (Bergsträsser, 1779) (Lepidoptera: Lycaenidae: Polyommatinae) discovered in Van Province, Türkiye, with notes on its habitat and implications for conservation

A population of dusky large blue Phengaris nausithous (Bergsträsser, 1779), an obligately myrmecophilous lycaenid butterfly species with endangered status according to the International Union for Conservation of Nature Red List for Türkiye, was discovered for the first time in Van Province, Eastern Türkiye. Here, the species inhabits tall-grass, damp meadows in a valley in the natural water system of Büyük Creek (Dönemeç Stream), above 2000 m a.s.l. This population is completely isolated from any recorded populations by at least 200 km distance and is threatened by various anthropogenic effects, including changes in agriculture practices, drainage and road construction. The habitat and food plant situation are described and biogeographical and conservation implications are given. Further systematic studies of similar habitats in the region are recommended to fully document and understand the distribution and population size of the species in Van Province. As the ant-host of P. nausithous in the region is unknown, study of the myrmecophilous relationship is also desirable to work out efficient conservation measures.