(Ochsenheimer, 1808)
Eros Blue
Description:
The Eros Blue is a mountain butterfly occurring on sub-alpine and alpine grasslands, on rocky places with flower-rich vegetation and on scree slopes. The females can be seen both on the short turf where these food plants grow, as in taller grassland where there are many nectar plants in bloom. The males often congregate to drink from damp ground. Purple Beaked Milk-vetch (Oxytropis halleri) and O. fetida are probably its major food plants but other leguminous plants such as Astragalus sempervirens, A. leontinus, and Common Birdsfoot-trefoil (Lotus corniculatus) have also been named.
The caterpillars feed on the leaves of the food plant and hibernate on it. In spring, they grow further and when fully grown, pupate at the foot of the food plants.
The Eros Blue has one generation a year.
Habitat:
Alpine grasslands
Dry calcareous grasslands
Screes
Similar species:
Polyommatus eroides
Aricia anteros