Description and notes
Identification keys and general biology are given in Spooner (1954), Morgan (1984), Falk (1991) and Kunz (1994).
Kimsey and Bohart (1990) treat O. puncticollis as a variety of O. aeneus (Fabricius), as do some other authorities. The specimens from Yorkshire, named as O. aeneus, could therefore be considered as showing characters intermediate between O. aeneus and O. puncticollis. Similarly, Shaw's (1998) Scottish specimen named O. puncticollis, could also be an intermediate form. However, specimens recorded from south of Yorkshire are always clearly O. aeneus or O. puncticollis.
Scarce from South Devon to West Kent, north to Denbighshire, Staffordshire, Warwickshire, Cambridgeshire and Norfolk. There is also an isolated record from Scotland (Dalkeith, Midlothian) (Shaw, 1998).
Overseas, the species is often treated as a variety of O. aeneus when found in Europe (including The Netherlands, Belgium, France, Spain, Germany, Switzerland and Italy), north Africa and western Asia.
Status (in Britain only)
This species is regarded as being Rare in Shirt (1987) and as Notable A by Falk (1991).
Found in the open habitats of its stem-, gall- and wood-nesting hosts.
Usually July, but also June and August.
Unknown, but probably a brood parasitoid on small stem and wood-nesting crabonid wasps.