The first observation of Euphydryas aurinia (Lepidoptera, Nymphalidae) developing on Gentiana cruciata in Lithuania

A population of the endangered butterfly Marsh Fritillary Euphydryas aurinia, using exclusively Gentiana cruciata as a larval food plant, was recorded for the first time in the valley of the Dksta river (Vilnius administrative district) in Lithuania . Caterpillars were observed both in summer when they lived gregariously in numerous webs spun on gentians, and in spring when they were feeding on new shoots or basking in the sun. The butterfly is...