Establishment and identity of exotic parasitoids of Bemisia tabaci in Arizona

A large multi-institutional, interagency classical biological control program was initiated in the early 1990s to combat the invasion of the B biotype of Bemisia tabaci into the USA. Using both morphology and RAPD-PCR, the establishment of two exotic parasitoid species (Eretmocerus nr. emiratus and Encarsia sophia) attacking B. tabaci has been documented in Arizona. From 1996 through 2007 field research was conducted for B. tabaci on cotton in Arizona to examine whitefly dynamics and evaluate the potential impact of these exotic parasitoids on overall biological control. Although life table results suggest that predation provides the highest levels of natural mortality to populations of B. tabaci, parasitoids have and continue to provide a consistent level of mortality which contributes to biological control of this pest in the low desert agricultural production areas of Arizona. The exotic species appear to have completely displaced native Eretmocerus in the Arizona cotton system.