Successful colonization ofEretmocerus debachi (Hym.: Aphelinidae) in the eastern mediterranean citrus region of Turkey

Predicting the Risk of Biological Invasions Using Environmental Similarity and Transport Network Connectedness

Understanding the risk of biological invasions associated with particular transport pathways and source regions is critical for implementing effective biosecurity management. This may require both a model for physical connectedness between regions, and a measure of environmental similarity, so as to quantify the potential for a species to be transported from a given region and to survive at a destination region. We present an analysis of integrated biosecurity risk into Australia, based on flights and shipping data from each global geopolitical region, and an adaptation of the "range bagging" method to determine environmental matching between regions. Here, we describe global patterns of environmental matching and highlight those regions with many physical connections. We classify patterns of global invasion risk (high to low) into Australian states and territories. We validate our analysis by comparison with global presence data for 844 phytophagous insect pest species, and produce a list of high-risk species not previously known to be present in Australia. We determined that, of the insect pest species used for validation, the species most likely to be present in Australia were those also present in geopolitical regions with high transport connectivity to Australia, and those regions that were geographically close, and had similar environments.

Post-release evaluation of Eretmocerus hayati Zolnerowich and Rose in Australia

Bemisia tabaci biotype B is a significant pest of agriculture world-wide. It was first detected in Australia in 1994. Assessments of the potential of parasitoids already present in Australia to control this pest indicated that two species of Eretmocerus and 11 species of Encarsia were present, but they did not exert sufficient control with a combined average of 5.0+/-0.3% apparent parasitism of 4th instars. Further, only 25% of samples containing biotype B had parasitised individuals present. The surveys also identified that fewer B biotype were being parasitised compared with the Australian indigenous biotype. Overall, Er. mundus was the most abundant parasitoid prior to the introduction. Previous research indicated that Er. hayati offered the best prospects for Australia and, in October 2004, the first releases were made. Since then, levels of apparent parasitism have averaged 29.3+/-0.1% of 4th instars with only 24% of collections having no parasitism present. Eretmocerus hayati contributed 85% of the overall apparent parasitism. In addition, host plants of the whitefly with low or no parasitism prior to the release have had an order of magnitude increase in levels of parasitism. This study covers the establishment of the case to introduce Er. hayati and the post-release establishment period November 2004-March 2008.