Submitted to: Biological Control
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/20/2004
Publication Date: 11/1/2004
Citation: Goolsby, J., Debarro, P., Kirk, A., Sutherst, R., Canas, L., Ciomperlik, M., Ellsworth, P., Gould, J., Hartley, D., Hoelmer, K.A., Naranjo, S.E., Ruiz, R., Vacek, D. Post-release evaluation of biological control of Bemisia tabaci biotype "B" in the usa and the development of predictive tools to guide introductions for other countries. Biological Control. 32: 70-77 Interpretive Summary: In this paper we analyze the results of the classical biological control program conducted in the USA during the mid 1990s for Bemisia tabaci; and use this information to select the most appropriate biological control agent for release in Australia. The analysis of the program takes place ten years after the final release of biological control agents in the southwestern USA. We determined that the pre-release quarantine studies of the candidate biological control agents and knowledge of the climates in which they evolved were valuable predictors of their eventual establishment and success in the field. The most successful parasitoids were in the Eretmocerus species collected from B. tabaci in the Old World that performed well in the quarantine studies and came from climates similar to the southwestern USA. In addition, these species have a more narrow host range than the endemic Eretmocerus tejanus and Eretmocerus eremicus of North America, which may also account for their competitive advantage in the field. For Australia we recommended release of Eretmocerus hayati originally collected in Pakistan and now established in Texas, since it is known to perform well in the field and the climate in the areas of Australia most impacted by B. tabaci was most similar to Texas.
Technical Abstract: Climatic matching and pre-release performance evaluation were useful predictors of parasitoid establishment in a retrospective analysis of the classical biological control program against Bemisia tabaci biotype 'B' in the USA. Laboratory evaluation of 19 imported and 2 indigenous parasitoid species in quarantine on B. tabaci showed that the Old World Eretmocerus spp, had the highest attack rate. The climate-matching program CLIMEX was used to analyze the establishment patterns of five Old World Eretmocerus spp. introduced to the Western USA. The top matches ± 10% for the climate of the area of introduction and origin of the introduced parasitoids always included the species that established. The Old World Eretmocerus spp. came from regions characterized by many separate biotypes of B. tabaci other than 'B', but are considered specialists of the B. tabaci complex as compared to the indigenous North American oligophagous Eretmocerus spp. This narrower host range and high attack rate combined with climatic adaptation may account for their establishment in the USA. A set of predictive tools and guidelines were used to select the best candidate for importation and possible release into Australia that has been recently invaded by the 'B' biotype. The establishment patterns of the introduced Eretmocerus spp. and a comparison of climates of their respective locations in the USA were compared with the affected area in Australia. The best climatic match was the Lower Rio Grande Valley of Texas suggesting its dominant parasitoid, E. hayati ex. Pakistan be considered as the first candidate for evaluation as a biological control agent.