Image Credit: Christophe Quintin
Primitive Wasps (sawflies: Tenthredinidae) – herbivores – In most communities I have personal studied, sawflies are numerous and diverse flower-visitors. They seem to limit the types of flowers they visit to bowl-shaped ones. There might also be a connection between floral choice and their larval host-plants.
Sawflies are rather unique “wasps” that do not have a constriction between their thorax and abdomen. They come in many color patterns.
Primitive Wasps (ichneumons: Ichneumonidae+) – parasitic on herbivores –-Integrated Pest Management techniques provide for biological control agents (particularly parasitic wasps) by planting rows of flowering plants placed adjacent to crops to serve as nectar sources and mating sites. With certain very specific exceptions, I doubt that their presence is a significant boon to the actual pollination of the plants. However, expect to observe a large diversity of these parasitic wasps in the course of any multi-year study. There are probably more than 500 species in the PNW.
Ichneumonids, and the smaller braconids, are characterized by multi-segmented antennae (i.e., more than the 12-13 segments that bees and wasps all have).