Saturday, 19 December 2015

The Parasitic Fly Cistogaster globosa in Northants

Cistogaster globosa is a small but distinctive parasitic fly (Family Tachinidae) that is currently at its northern range limit in Northants. We have two records of it:
- a female at Bradlaugh Fields, Northampton in May 2011
- a male near Yardley Hastings in September 2015

Its main stronghold is the chalk of Berkshire and Wiltshire but it does pop up from time to time in other parts of south-east England. It is a parasitoid of the Bishop's Mitre Shieldbug Aelia acuminata. The two sites where it has been found in Northants are both flower-rich grasslands with fairly hot and dry soil conditions. It would be useful to see if this species occurs in similar habitats in other parts of Northants, particularly more northern sites as it might be expanding its range. Its current distribution can be found here:

Cistogaster globosa male. The female is is similar in shape and size but does not have the golden markings.