Reproductive biology and search behavior of Amitus bennetti (Hymenoptera :Platygasteridae), a parasitoid of Bemisia argentifolii (Homoptera : Aleyrodidae)

Amitus bennetti Viggiani & Evans is a recently discovered parasitoid of whi teflies in the genus Bemisia, including the serious pests Bemisa tubaci (Ge nnadius) and Bemisia argentifolii Bellows & Perring. The reproductive biolo gy and the host searching behavior of A. bennetti was studied in the labora tory, using B. argentifolii as a host. The developmental time for A. bennet ti from egg to adult at 27 degrees C was 21.4 +/- 0.2 d (range, 18-31 d). T he primary behavioral pathway when searching for hosts was searching, groom ing, host encounter, host antennation; followed by probing a host. Searchin g occupied 44.9% of the adults' time budget, whereas grooming represented 2 7.1%. There was a significantly greater preference to antennate and probe 1 st and 2nd instars than older instars. Average longevity ofA. bennetti adul ts 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 n umber of progeny produced in the daily fertility study was 78.8 +/- 8.1 (ra nge, 47-122) female offspring per female; no males were produced in any exp eriment or colony. Life tables were constructed assuming a preimaginal surv ival of 100%, and yielded a net reproductive rate (R-o) of 73.1, a cohort g eneration time (T-c) of 21.7 d, and an intrinsic rate of increase (r(m)) of 0.199, the highest ever recorded for a parasitoid of Bemisia spp. This par asitoid may be a suitable candidate for use in inundative release programs targeting Bemisia spp, whiteflies.