Biological characteristics of Evania appendigaster (L.) (Hymenoptera: Evaniidae) in different densities of Periplaneta americana (L.) oothecae (Blattodea: Blattidae)

Evania appendigaster (L.) is a solitary endoparasitoid of oothecae of the American cockroach, Periplaneta americana (L.). In this work we report our studies on the parasitism of P. americana oothecae by E. appendigaster and the biological characteristics of this egg parasite, as it is affected by host density and mating. Cockroach oothecae were presented for individual females at different densities (one, two, three, four, five and six oothecae) during 2 days of exposition time. Reproduction was determined to be biparental and arrhenotokous. Host density did not influence sex ratio and longevity. The greatest reproductive efficiency of the females occurred in the first 14 days of their lifetime. At higher densities low parasitism rates were accompanied by a high percentage of dead oothecae. The percentage of parasitism decreases with increase in host density.