A very biodiverse and important group. Many are valuable biocontrol agents that control populations of agricultural and forest pest insects. Wasplike in appearance, but (with rare exceptions) do not sting.
POLYDNAVIRUSES. Two subfamilies of Ichneumonidae (Campopleginae and Banchinae) and 6 subfamilies of Braconidae (Microgastrinae, Miracinae, Cheloninae (including Adeliinae), Cardiochilinae, Khoikhoiinae, and Mendesellinae) carry polydnavirus DNA in their genomes, and release polydnaviruses into the host when the eggs are injected. The polydnaviruses suppress the host's immune system, thus protecting parasitoid progeny from host defenses.(2)