#365Insects 39: #Orussus terminalis (Newman, 1838)
Although considered sawflies, the #Orussidae are special in that rather than feeding directly on wood and other plant material like traditional sawflies, they actually feed on the other insects munching through trees. It’s thought that the common ancestor of these Parasitic Wood Wasps and the rest of the non-sawfly Hymenoptera (including parasitic wasps, social wasps, bees, and ants) was the origin of parasitism in Hymenoptera, a strategy that would in turn lead to an explosive radiation of diversity within the order. (at University of Guelph)