Parasitic wasps are important natural enemies of several insect pests. They use a variety of methods to modulate their insect host for their progeny to develop. For example, the female wasp needs to avoid or suppress the host immune responses by introducing venom with or without virus like particles and/or polydnaviruses. The aim of this paper is to provide a synthesis of current knowledge regarding the immunosuppression of host immunity with venom in parasitoids that are devoid of symbiotic viruses. Special emphasis is given through disabling host hemocytes by venom of the endoparasitoid Pimpla turionellae (Hymenoptera: Ichneumonidae) with comparisons of venoms from other parasitoid species.