Holly blue: This little piece of flying sky is a butterfly of woods, hedgerows and gardens. The female has broad black borders to the wings, while those of the male are clear blue and resemble the common blue. It can be distinguished by the silver with small black spots undersides of the wings whereas the common blue has the underside brown with black and orange spotting. More useful is that the holly blue, being a butterfly of trees and bushes, flies much higher than the common blue that is a butterfly of meadows and stays close to the ground – usually! The holly blue is unusual in having two generations a year where the caterpillars of each generation have different food plants. The adults flying now, in the Spring, have emerged from pupae that have overwintered. After mating the females lay eggs on the flower buds of holly. The caterpillars will eat the flower buds and such damage can be seen. After two or three weeks as a pupa hidden in leaf litter the adults emerge. This generation emerges in July and lays eggs in the flower buds of ivy. It is the pupae from these caterpillars that will over winter. This butterfly should, really, be called the holly and the ivy blue!
Photos Robert Maxwell Wood