The Holly Blue

The most frequent butterfly visitor to our garden is the Small White Pieris rapae, two or more can be seen throughout most days. This year I have recorded the Gatekeeper Pyronia tithonus, also know as the Hedge Brown, the Small Tortoiseshell Aglais urticae, the Painted Lady Vanessa cardui (cracking latin name) and the Peacock Inachis io. But my favourite has to be the diminutive Holly Blue Celastrina argiolus.

The butterfly in the photo is a female Holly Blue that visits our garden fairly regularly, here seen on a jasmine plant. Not a brilliant pic because she refused to open her wings fully as I repeatedly pressed the shutter release. But the black wing tips help to identify this as a female. The lilac-blue male can be confused with the Common Blue Polyommatus icarus. The black borders of the Holly Blue female are bolder near the wing tips.

Populations of the Holly Blue vary greatly from year to year due mainly to a combination of the climate and the presence of a parasitic ichneumon wasp called Listrodomus nycthemerus. This black and yellow insect parasites only the Holly Blue and kills large numbers of its caterpillars.

The parasitic wasp Listrodomus nycthemerus