Mating and Oviposition of Three Encarsia Species (Hymenoptera : Aphelinidae) on the Greenhouse Whitefly, Trialeurodes vaporariorum (WESTWOOD) (Homoptera : Aleyrodidae)

Abstract

To select a promising agent for biological control of the greenhouse whitefly, Trialeurodes vaporariorum (WESTWOOD), mating and oviposition behaviors of two native species, Encarsia sp. (A) and Encarsia sp. (B), and an introduced one, Encarsia formosa GAHAN, were observed. Mating behavior of Encarsia sp. (A) and Encarsia sp. (B) differed from that of E. formosa : the male of the former two species mounted the female before and after copulation, while the male of the latter did not. Encarsia sp. (A) and Encarsia sp. (B), which are arrhenotokous, laid fertilized female-producing eggs in healthy whiteflies, and unfertilized male-producing eggs on fully-grown larvae or pupae of E. formosa in whitefly pupae. The thelytokous parasitoid E. formosa laid all its eggs in unparasitized whiteflies, but the mechanism of its male occurrence is not clear. Fecundities of Encarsia sp. (A) and E. formosa were similar to each other and higher than that of Encarsia sp. (B).