Artificial diets that will support adult silverleaf whiteflies (SLWF) for 10-15 days have been developed and used to test the toxicity of potential insecticidal compounds. Mean SLWF longevity was not significantly different on diets containing sucrose and either yeast extract or FreeAmineIIITM (a mixture of amino acids) or sucrose and both yeast extract and FreeAmineIII. Photorhabdus luminescens is an enteric symbiont of Heterorhabditid nematodes. These nematodes, upon invading a host insect, regurgitate the bacterium into the hemocoel. The bacteria multiply rapidly creating a raging septicemia that results in the death of the insect. P. luminescens produces a wide array of factors and toxins which disable the immune system of many insects and kill and digest them. Toxin complex A is composed of three gene products, TcaA, TcaB, and TcaC. TcaA and TcaB, in turn, contain three (TcaAi, TcaAii and TcaAiii) and two (TcaBi and TcaBii) subunits, respectively. Diets containing P. luminescens toxin complex A with or without subunit TcaAiii, a 66 kDa peptide, reduced the percent survival of adult SLWFs in a similar dose-dependent manner. Thus, the presence of TcaAiii does not appear to be required for the observed toxicity of P. luminescens Toxin complex A.
Species 1: Homoptera Aleyrodidae Bemisia tabaci (silverleaf whitefly, sweetpotato whitefly Biotype B)
Keywords: Photorhabdus luminescens toxin, artificial diet
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