Reproductive Biology and Search Behavior of Amitus bennetti (Hymenoptera: Platygasteridae), a Parasitoid of Bemisia argentifolii (Homoptera: Aleyrodidae)

Amitu8 bennetti Viggiani & Evans is a recently discovered parasitoid of whiteflies in the genus Bemisia, including the serious pests Bemisa tabaci (Gennadius) and Bemisia argentifolii Bellows & PelTing. The reproductive biology and the host searching behavior of A. bennetti was studied in the laboratory, using B, a'rgentifolii as a host. The developmental time for A. bennetti from egg to adult at 27'C was 21.4 ± 0.2 d (range, 18-31 d). The primary behavioral pathway when searching for hosts was searching, grooming, host encounter, host antennation, followed by probing a host. Searching occupied 44.9% of the adults' time budget, whereas grooming represented 27.1%. There was a significantly greater preference to antennate and probe 1st and 2nd instars than older instal'S. Average longevity of A. bennetti adults exposed to hosts was 6.3 ± 0.9 d (range, 3-11 d). Oviposition occurred on days 0-6 of adult life, but was concentrated in days 0-3. The average number of progeny produced in the daily fertility study was 78.8 ± 8.1 (range, 47-122) female offspring per female; no males were produced in any experiment or colony. Life tables were constructed assuming a preimaginal survival oflOO%, and yielded a net reproductive rate (Ra ) of73.1, a cohort generation time (Te) of 21.7 d, and an intrinsic rate of increase (rm) of 0.199, the highest ever recorded for a parasitoid of Bemisia spp. This parasitoid may be a suitable candidate for use in inundative release programs targeting Bemisia spp. whiteflies.