www.ukbutterflies.co.uk

Here's something that might be of interest. I spotted a few of these large flies, which are of similar size to a bumble bee, at Gait Barrows and Foulshaw Moss when I was hunting fritillaries back in July. I've finally managed to get an identification with the help of a member of my local naturalist's society. The fly is called Tachina Grossa and apparently it's a parasite of large caterpillars, which I presume would include the fritillaries.