I have a confession to make. Until yesterday, I hadn’t found a new fly family for more than a month, and not for lack of trying. I have had two full days searching in prime Scottish habitats at the end of Dipterists Forum field meeting in Stirling, as well as several trips to different places in East Lothian; I have found lots of flies, but all in previously found families. The families that I am missing are mostly those with very few species, often obscure flies at the limit of their range in southern England and that I wouldn’t expect to come across. A few others are parasites of bees, bats or birds and will require a bit of specialist help to find. However, there are three reasonably common families that are still missing from my list – Conopidae (Thick-headed flies), Therevidae (Stiletto flies) and Platypezidae (Flat-footed flies) – and I thought that if I knew where to look I might be able to turn them up.
The larvae of Conopidae are parasites of bees and wasps, the adults then feeding on flowers, with the females waiting for a victim to turn up before pouncing on them, prising their abdominal segments apart and injecting an egg. So one sunny day, getting tired of my labours in the garden, I took a walk down to the river where I knew there were some good banks of flowers. There were lots of hoverflies and tachnids, as well as butterflies, ichneumon wasps, beetles and then for a moment a wasp that wasn’t quite a wasp, long antennae at the front, and I kneeled down for a better look, regretting not having a tube or a net in my pocket, but memorising its features before it took off – black and yellow striped abdomen, slightly waisted and swollen at the tip, a black thorax with yellow spots at the shoulders. When I was almost back at the house I spotted another one on a patch of thistles, rushed back for my net and with a bit of persistence, located and caught it.
There is something about this fly that reminds me of Tom the cartoon cat – though I am not sure I can explain why! Perhaps it’s the ridiculous antennae (like ears?), the elongated proboscis, the enormous head and general look of bumbling purposefulness. In any event, this is a superb fly and should it happen to be my last new family for the year it would be a fitting way to finish, though I haven’t given up yet!