Gonia picea (Pete Kinsella)
The afternoon of 22nd March 2020 was warm and sunny at Hightown dunes, Merseyside. There were plenty of insects on the wing and I had found good numbers of Vernal Mining Bees (Colletes cunicularius) and Syrphidae, including Cheilosia grossa.
My attention was drawn to a large and rather dark looking fly sat on a nearby grass stem. It appeared to be a tachinid, but seemingly one that I was unfamiliar with. It was about a centimetre in length, with a large head and a distinctively pale and swollen frons. The scutellum was pale and there were silvery bands running laterally across the abdomen. I managed to obtain a record shot before it flew off. Later, after checking online and consulting with Dr Phil Smith, it appeared that the fly was Gonia picea, a species of tachinid not previously recorded on the Sefton Coast. This species is also new to vice county 59 (South Lancashire) according to Matt Smith of the UK Tachinid Recording Scheme.
Gonia picea (Pete Kinsella)
G. picea is primarily a southern species in the UK, although there are records for East Yorkshire and most recently also found by John Wright in Darwen (VC59) on 5th April, and on three occasions by Mo Richards in central Lake District, also in April 2020. The larvae of G. picea parasitise the caterpillars of Lepidoptera, in particular, those of the Antler Moth (Cerapteryx graminis). Following this sighting, I recorded G. picea on a further four occasions at Hightown dunes during the subsequent four weeks, with the last record in late April. This suggests range expansion of this species is occurring and that it may become established at this site.
