Tachina grossa (St Davids, wales)


In general I am pretty positive about nature; I try to find some beauty or wonder in everything but what can I find to like about this? It is ugly, dirty and evil! It is a parasitic fly called Tachina grossa and it is certainly gross. It is quite common on heathland in August and September and in flight it looks like a bumble-bee but when it settles it becomes quite obvious very quickly that it is not a cute little furry insect but a rather disgusting fly.

It parasitises large caterpillars by laying its eggs inside them. The larvae then eat the insides of the caterpillar before pupating and overwintering as a pupae. Given its liking for large caterpillars and heathland I expect the large, woolly caterpillar of the fox moth is a favoured target as they, too, are quite common in late summer.

However unpleasant it still has a role to play in the wider scheme of things and so I guess its \\\’live and let live\\\’!