Ms Holly Blue

Today's the day ........................ for a vicious circle

Lots of Holly Blues in the garden today - always a delight to see.  This one is a female because of the dark edges to the wings.

I've been doing a bit of researching into these butterflies and it seems that they very much have a love/hate relationship with that rather sinister creature - the parasitoid ichneumon wasp (Listrodomus nycthemerus).  And when I say love/hate, it's more along the lines of the wasps love the holly blues, who absolutely hate them.

The wasp lays an egg on a holly blue caterpillar, inserting the egg into the caterpillar's body and the adult wasp emerges from the chrysalis, killing the chrysalis before its emergence.  Even more weird is the fact that the population of the butterfly is tracked by that of the wasp so that when butterfly populations are low, the wasp population falls and this allows the butterfly population to increase.  This, in turn will result in an increase in the population of L. nycthemerus as there are more hosts available to be parasitised.  Then the whole cycle begins again as more caterpillars are parasitised and the butterfly population crashes.

It's a tough world out there ......................