Effect of host experience of the greenhouse whitefly, Trialeurodes vaporariorum, on trap cropping effectiveness

摘要

This study evaluated whether experience of Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) on a poinsettia cash crop, Euphorbia pulcherrima Willd. ex Koltz (Euphorbiaceae), influences the effectiveness of an eggplant trap crop, Solanum melongena L. (Solanaceae). Two whitefly strains were tested: one was reared on poinsettia (poinsettia-strain) and a second was reared on bean [Phaseolus vulgaris L. (Fabaceae)] (bean-strain). We first determined whether host experience altered the preference of adult whiteflies for eggplant and their survivorship on poinsettia. Then, we determined whether changes in the preference and/or survivorship influenced the effectiveness of the trap cropping. Adult whiteflies from both strains consistently redistributed and settled on an eggplant trap crop in significantly higher numbers compared to poinsettia. The adult survivorship of the poinsettia-strain whiteflies was slightly higher on poinsettia than on the bean-strain. In research greenhouse experiments, we found that the trap cropping consistently resulted in a decrease in the density of the poinsettia-strain whiteflies on the cash crop compared to that in monoculture. However, higher adult whitefly survivorship on eggplant than on poinsettia could compromise its effectiveness as a trap crop in poinsettia. The effectiveness of trap cropping, as reflected by the whitefly density reduction on a poinsettia cash crop, was significantly smaller than the attractiveness of the trap crop, as indicated by the whitefly abundance on an eggplant trap crop.