Holly Blue (Celastrina argiolus)
Is the Holly Blue not an adorable little butterfly? Totally exquisite when seen close up!
The Holly Blue is also a fascinating little creature. The insect over winters as a pupae, usually hidden in amongst Ivy. In April (there seem to have been quite a number this year) they emerge, mate and lay their eggs on Holly flowers. First broods will be gone by early June and then the eggs from the first brood (laid on Holly) emerge, mate and lay their eggs on Ivy. The larvae pupate and over winter in amongst the Ivy and so the cycle continues. Second broods are only briefly on the wing in late July/early August.
Most 'blues' are grassland species but the Holly Blue is, because of its affinity to the Holly and the Ivy, more at home in woodlands, shrubby areas and gardens. It is the most likely blue you will see in your garden in most areas.
The other feature of the Holly Blue is wonderful silver colour with black spots on the under wing. It is possible to detect the silvery colouring even when the butterfly is in flight.