With no type of natural control in Tahiti, the excessive number of glassy-winged sharpshooters was a major social, economic, and agricultural nuisance on the island. The pest was especially present in high numbers in urban areas along the coast where it was severely affecting the health of trees and bushes upon which massive numbers of pests were feeding. When the islands government scientists approached Hoddle for guidance in 2003, he agreed to assist.
After safety evaluations, Hoddle and his colleagues released nearly 14,000 parasitic wasps at 27 sites in Tahiti between May 2005 and October 2005, resulting in rapid parasitism of glassy-winged sharpshooter eggs. By December 2005, the wasp had colonized the entire island of Tahiti, and glassy-winged sharpshooters decreased in number at all study sites to less than 5 percent of their original population density.
As a result of the rapid and dramatic reduction in the population of the glassy-winged sharpshooter in Tahiti, several problems associated with the pest diminished, such as excessive feeding on plants, high levels of sharpshooter excrement raining from trees, and home and shop invasions by hundreds of sharpshooters at night due to the pests attraction to lights.
Populations of the glassy-winged sharpshooter have been successfully maintained at a very low level in Tahiti for over two years, the time our experiments ended, Hoddle said. Tahitian farmers have said their fruit production has improved in comparison to years when the sharpshooter was in abundance. The success of biological control with host-specific natural enemies demonstrates that alternative technologies that are not chemically driven can be ve
|Contact: Iqbal Pittalwala|
University of California - Riverside