Description and notes
Identification keys and general biology are given in Morgan (1984) and Falk (1991). Previously known as C. helleni Linsenmaier, 1959. Kunz (1994) considers C. bicolor Lepeletier, 1805 and C. illigeri to be the same species. Morgan (1984) separates these two names, with C. bicolor only known from Jersey.
Cornwall to Kent, and north to Leicestershire and West Norfolk. (Morgan (1984) also gives Nottinghamshire, but no data are available). Jersey.
Overseas, the wasp occurs in Europe (including Norway, Sweden, Finland, The Netherlands, Belgium, Luxembourg, France, Switzerland, Italy, Poland, Austria and Hungary).
Status (in Britain only)
This species was not listed in Shirt (1987), but was included by Falk (1991) (as C. helleni) in the category Notable B (now known as Nationally Scarce (Nb).
Open sandy habitats such as lowland heathland, coastal sand dunes, gravel and sand pits.
Females active from June to September but mainly during July and August. Males active from June to August but mainly during July.
Apiaceae (Umbelliferae) and hemp-agrimony.
No specific information found.