On 23rd May 2025, at a Tanyptera recording day at Hightown Dunes on the Sefton Coast, a surprising discovery was made: Phorbia penicillaris, a fly never before recorded in Britain. The find was amongst 74 fly species collected during four hours of sweep-netting by P. Brighton. In the field, P. penicillaris, appeared to be an unremarkable, dark, bristly Calyptrate, requiring examination under a microscope for species identification – typical of almost all flies in this group.
Later examination of the specimen revealed a unique brush of hairs on its genitalia, a feature that confirmed it as P. penicillaris. This species has a wide distribution across Europe, from Germany and Scandinavia to France and Hungary, and even as far afield as North America. It is often found in dunes and sandy habitats, making Hightown Dunes – 60 hectares of grassland, scrub, reed-bed, and saltmarsh – a typical setting.
What makes this record particularly intriguing is the possibility that the species may already have a small, overlooked colony on the Sefton Coast. The specimen’s worn wings could suggest long travel, but its presence in a suitable habitat indicates it might be breeding locally. With an active community of insect photographers and recorders on the Sefton Coast, future sightings may soon confirm whether P. penicillaris has an established colony.
A detailed account of this finding is due to be published in the next edition of Dipterists Digest.
