Monday, December 10, 2007 - 8:53 AM

The efficacy of trap crops to enhance biocontrol programs for whitefly management in poinsettia greenhouses in British Columbia, Canada

Tara L. Moreau, and Murray B. Isman, University of British Columbia, Faculty of Land and Food Systems, MCML 248 - 2357 Main Mall, Vancouver, BC, Canada

The whitefly is considered to be one of Canada’s priority greenhouse pests due to the development of whitefly resistance to chemical pesticides and yield losses associated with whitefly damage. The main whiteflies found in Canadian greenhouses are the greenhouse whitefly (Trialeurodes vaporariorum) and the silverleaf or sweetpotato whitefly (Bemisia species). Natural enemies can effectively be used to control whitefly populations on certain crops and growing conditions; however, biological control programs do not always meet growers’ pest management needs. Agricultural entomologists have proposed using trap crops and/or banker plants in biocontrol programs as a means of enhancing whitefly control whilst improving the cost-effectiveness of natural enemies. Ongoing commercial poinsettia trials in Ontario have demonstrated some success using eggplant (Solanum melongena cv. Baby Bell) as a trap crop for whiteflies. This previous work has highlighted important questions and areas requiring further research.

The objective of this research is to determine if trap crops improve the efficacy of whitefly management within commercial sweet pepper (Capsicum annuum) and poinsettia (Euphorbia pulcherrima) greenhouses in British Columbia. The practice of trap cropping is an example of deliberate manipulation of a pest’s behaviour for the purpose of pest management. This work focuses on evaluating whitefly preference and performance on cash crops (sweet pepper and poinsettia) and trap crops (eggplants) using laboratory choice bioassays, small greenhouse experiments and commercial greenhouse trials. An overview of the results found to date will be presented and further avenues of study will be discussed.

Species 1: Hemiptera Aleyrodidae Trialeurodes vaporariorum (greenhouse whitefly)
Species 2: Hemiptera Aleyrodidae Bemisa argentifolii (silverleaf whitefly, tobacco or sweet potato whitefly)