The Orrusidae are unique in having their antennal sockets below, rather than between, the eyes. There are species present across the globe but the greatest diversity is found in Africa in tropical and subtropical zones. Globally, there are 75 species in sixteen genera.
The Orrusidae are unique being the only parasitic wasps outside of the Apocrita and are considered as a sister group to the Apocrita. Larvae are parasitoids of wood boring jewel beetle larvae, which are uncommon in Britain. Benson states that they are internal parasites whilst Goulet gives them as external parasites.
In Britain there are two historic records of the species Orussus abietinus. However, in the absence of specimens, Benson considered the presence of this family in Britain as extremely doubtful.
Genus Orussus Latreille, 1797
Orussus abietinus (Scopoli, 1763)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Liston A, Knight G, Sheppard D, Broad G, Livermore L (2014) Checklist of British and Irish Hymenoptera - Sawflies, ‘Symphyta’. Biodiversity Data Journal 2: e1168. https://doi.org/10.3897/BDJ.2.e1168