Biology and biogeography of the chalk-hill blue Polyommatus coridon - Insect of the year 2015 for Germany, Austria and Switzerland

Abstract

The chalk-hill blue was nominated insect of the year 2015 for Germany, Austria and Switzerland. The species is strongly associated with base-rich short-turfed swards; the caterpillars feed mainly on horseshoe vetch Hippocrepis comosa and show myrmecophilous behaviour. The species is restricted to Europe, where it is widely distributed but missing from the northern parts of the continent. Polyommatus coridon survived the last ice age in Mediterranean refugia in Italy and the Balkan Peninsula from where it colonised more northern regions postglacially.