Identification key and general biology are given in Morgan (1984). Kunz (1994) considers C. bicolor and C. illigeri (Wesmael 1839) to be the same species. Morgan (1984), however, separates these two names.
Only recorded from Jersey in the Channel Islands.
Overseas, the wasp occurs throughout northern, middle and eastern Europe (including Sweden, Finland, The Netherlands, Belgium, Luxembourg, France, Spain, Germany, Switzerland, Italy, Poland and Hungary).