|Gerling, Dan - TEL AVIV UNIV|
Submitted to: Proceedings, XXI International Congress of Entomology
Publication Type: Abstract Only
Publication Acceptance Date: February 28, 2004
Publication Date: August 15, 2004
Citation: Gelman, D.B., Gerling, D. 2004. host-parasite interactions between whiteflies and their parasitoids. Proceedings, XXI International Congress of Entomology. Brisbane, Australia 8/15/04-8/21/04 Technical Abstract: Whiteflies attack more than 500 different species of plants and are serious pests of crops worldwide, causing billions of dollars in damage. Wasp parasitoids have a great deal to offer as insect control agents. They use a wide variety of mechanisms to manipulate their host's physiology and biochemistry to create an environment that is conducive to their own development. While there is considerable information concerning the host-parasite interactions that occur between lepidopterans and their parasitoids, little is known about the interactions between whiteflies and their parasitoids. Currently, there is no evidence to support the use of wasp-associated polydnaviruses or venom in redirecting whitefly metabolism, including interfering with the immune response. The production of teratocytes by whitefly parasitoids has been observed for Encarsia berlesei and Encarsia citrina. It has been suggested that these cells may play a role in protecting the parasitoid against intra and interspecific competitors. Manipulation of hormone titers, especially of molting and juvenile hormone titers, so common in parasitized lepidopterans, also occurs in parasitized whiteflies. In the Eretmocerus-Bemisia system, ecdysteroid titers decrease upon parasitization. However, E. formosa developing in both the greenhouse whitefly (Trialeurodes vaporariorum) and the sweet potato whitefly (Bemisia tabaci, biotype B) will not molt to its 3rd (last) instar until the whitefly has initiated adult development, a time when host ecdysteroid titers are known to peak. In the Trialeurodes lauri-Encarsia scapeata system in which host and parasitoid enter diapause in mid-summer, it appears that E. scapeata is able to trigger the initiation of its host's development. These and other host-parasite interactions will be discussed.