Liverpool workshop & Bithia demotica/modesta

Back at the end of 2024 Leanna Dixon at the Tanyptera Project, based at Liverpool World Museum, invited us to come and run a tachinid workshop on the 13th September 2025. We’re just back from the day and can report that it went very well indeed and we all had a great time. Fourteen people, with a wide range of expertise, signed up and kept Matt & myself busy fielding questions and loaning out specimens.

The facilities at the World Museum are very good, with a light and airy lab next to an excellent collection which we had laid out on the benches for people to examine.

Besides everyone’s enthusiasm for tachinids and the warm welcome of Leana and Gary Hedges, the museum team, the highlight for me came right at the end of the day when Nicola Garnham spotted some “Bithia modesta” in the collection, a species that I had been meaning to double-check since Peter Chandler queried the status of demotica/modesta a few weeks ago. Since we added Bithia demotica in 2006 I had not had time to track down and examine the B. modesta in collections as it is quite a rare species.

The 2 male specimens had been pinned beautifully by C.D. Day, back in 1950 & 53, and he’d done a good job to hook out the genitalia properly so it was easy to see that they were in fact Bithia demotica!

Above is my original iPhone closeup of the male genitalia and another more detailed one by Gary on the museum’s stacker. The females of Bithia demotica & modesta can be very tricky to determine but the males are very easy – demotica having sinuous circi when viewed from the side, terminating in an obvious sharpened hook (see below). The surstyli also have a slightly more pointed tip in demotica.

So, with this discovery I would encourage anyone with Bithia modesta specimens to check them and report back your findings to me 🙂

The data for both males was as follows:

• Chene Cliff
  Portland
  (male) 27-7-1950
  C.D. Day.
  Dorchester
• West Weare
  Portland
  (male) 8-7-1953
  C.D. Day.
  Dorchester