Warmer and, during the spring brood, drier weather in 2009 (compared with 2007 and 2008) led to larger numbers of Adonis at several sites and the species returned to some sites where none were seen in 2007/8. The number of known sites expanded from 4 (in 2008) to 6.

Male Adonis Blue (Polyommatus bellargus)
Photo © Clive Burrows

Female Adonis Blue on Horseshoe vetch Hippocreppis comosa, its larval foodplant.
Photo © Nick Bowles

However, the species is still not recorded at several sites on the edge of its range, where it had appeared to be establishing colonies at the start of this century. Hopefully this retraction is temporary and a return to warmer summers will see it bounce back into these sites. It is probably significant that these unoccupied sites seem to have more luxuriant and taller Horseshoe Vetch plants than the sites with the largest populations which have lower growing plants. Despite the apparent health of the taller plants they are probably providing cooler conditions for the Adonis Blue larvae resting beneath them, than the sparser, low growing plants at sites with larger populations.

Contact with the various landowners and policy makers continues to be regular and fruitful. These positive contacts and the interest of the landowners on whose private land the butterfly thrives lead us to some cautious optimism about the butterfly’s future within our region despite the species’ current fragile presence.