Grant: Applied Research and Development Grants - Level 1

Thrips are small insects that feed on a variety of agricultural crops and cause economic damage. Pest species like the western flower thrips (WFT), Frankliniella occidentalis, are serious pests of greenhouse-grown vegetables and flowers in British Columbia (BC) and elsewhere in Canada. Recently, problems have been reported with thrips on various field-grown crops in BC. Day-neutral strawberries produce fruit, not just during one fruiting period, but throughout the available growing season. Because day-neutral strawberry varieties are now grown more extensively in BC, strawberry flowers and fruits are susceptible to damage by thrips for a longer period and more damage is reported. Economic thresholds for WFT on strawberries are available from elsewhere in North America, but are not optimized for BC growers. In addition, no work has been done to determine the potential for using predatory insects for biological control of WFT on BC strawberries. In this project, laboratory and greenhouse trials will be done to develop a damage threshold for WFT on strawberries and to test the efficacy of biological control products on this pest. In addition to problems reported on strawberry, severe diebacks of potato plants have been recently observed in the presence of thrips. The dieback symptoms may be caused by Tomato Spotted Wilt Virus (TSWV) that is transmitted to plants by WFT, but the presence of TSWV in WFT has not been tested in BC populations. In this project, field-collected thrips and potato foliage will be tested for the presence of TSWV using DNA analysis. The research to be completed in this project will benefit pest management consulting companies by making their pest monitoring activities more precise. Increased precision in WFT management recommendations could result in reductions in the application of insecticide applications. Our work on WFT biological control could provide a more sustainable management strategy for this pest. Work to detect TSWV will aid in development of an explanation for thrips-associated diebacks in potato that have recently occurred.