Martin Harvey's picture

Tachinid fly, Gonia picea - Buckinghamshire

Observed: 25th April 2013 By: Martin Harvey
Berkshire Moth GroupFSC - Field Studies CouncilSoldierflies and Allies Recording SchemeBuckinghamshire Invertebrate Group
Invertebrates expert
Gonia picea - Coleshill Common - edit3
Gonia picea - Coleshill Common - edit2
Gonia picea - Coleshill Common - edit1

At a training day for the Chiltern Commons Project last week, someone pointed out these large flies that were buzzing around in some damp, tussocky grassland. They were unfamiliar to me, but key out to the tachinid fly Gonia picea, which parasitises noctuid moth caterpillars.
I've never encountered this fly before, and as far as I can tell this is the first record for Buckinghamshire, although like many insects that's more likely to be a result of under-recording rather than it being rare in the county.

Species interactions

No interactions present.


ophrys's picture


I took one, a first for Yorkshire, last March. Chris Raper commented that the species had a great year in 2012, being found in several new areas. Maybe that carries on in 2013? Fantastic fly!


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Martin D. Parr's picture

Thank you

Hi Martin,

Thanks again for a great session last week, and also for the fly ID - which Rachel passed on!
Great to know what it was and a new species to me!

Kind regards, Martin

Martin Harvey's picture

finding flies

Thanks Martin - and for anyone else reading this I should say that it was Martin Parr who first noticed these flies and asked me what they were, and since I didn't know that sparked off the further investigations!

Entomologist and biological recorder