BIVOLTINE BLUES: A SECOND GENERATION IN THE BRITISH CHALKHILL BLUE POLYOMMATUS CORIDON (LEPIDOPTERA: LYCAENIDAE)

摘要

We wish to report a very unusual case of bivoltinism in the British population of the Chalkhill Blue, Polyommatus coridon (Poda) (Lepidoptera: Lycaenidae). Polyommatus coridon is the second largest of the British Blues, with a wingspan of up to 40 mm,and the adults fly for 6-8 weeks between mid-July and mid-September. The species is locally common in southern England on south-facing chalk downland, and widespread in continental Europe. The distribution of this species is largely determined by the distribution of the larval foodplant, Hippocrepis comosa L. (Tolman & Lewington, 2008).