PARASITIZATION OF BEMISIA-ARGENTIFOLII (HOM, ALEYRODIDAE) BY ENCARSIA-PERGANDIELLA (HYM, APHELINIDAE)

The biology of the arrhenotokous autoparasitoid, Encarsia pergandiella Howard, was studied in the laboratory on the silverleaf whitefly, Bem isia argentifolii Bellows & Perring. Egg to adult development of paras itoid females averaged ca. 14 days at about 25.3+/-0.2 degrees C regar dless of whether the whitefly host was reared on tomato, eggplant or s quash. While all instars of B. argentifolii were accepted for primary parasitization, a greater percentage of third and fourth instars were parasitized. Mortality of whitefly nymphs in the absence of parasitiza tion did not differ among instars and averaged about: 35%. Second inst ar to pupal parasitoid females were accepted for secondary parasitizat ion although a greater percent of pupal females were parasitized. Abou t 40% of immature E. pergandiella females more than 4 days old died in the absence of secondary parasitization when exposed to adult E. perg andiella females.