The project initially aimed at assessing the potential of Eretmocerus mundus (APF) as a control agent for silverleaf whitefly (SLW). As the crops where SLW is a pest are annual, mechanisms of achieving early colonisation need to be assessed. Further, a broad range of pesticides are used in these crops and their potential impacts on the parasitoid are unknown. The capacity of E. mundus to control field infestations is also untested.

After the second year it was apparent that while E. mundus performed well under controlled conditions it lacked the ability to exert sufficient control on outbreaking populations. A decision was made to then to better understand the interaction between the native Bemisia tabaci and the exotic B biotype. The background to this shift was the observations that in the cotton growing areas of QLD SLW was patchily distributed and rarely found on cotton. In NSW, surveys of cotton in 1995 and 1996 found small numbers of SLW. Since then 100 leaves have been collected from more than 190 crops with no SLW being recovered. By way of contrast, in both NSW and QLD, the Eastern Australian Native (EAN) biotype of B. tabaci occurs commonly in cotton, although at densities of less than 3 individuals per leaf. The most common whitefly species in cotton remains the greenhouse whitefly (Trialeurodes vapororarium). The reasons for the low numbers of SLW was unclear but there were several possibilities. The most likely of these was an interaction between the two biotypes of Bemisia tabaci, climatic suitability and host availability.