Integrated Pest Management of Western Flower Thrips, Frankliniella occidentalis, in Off-season Strawberry Production

Nora Durham
Graduate (MS)
Luis Canas (Master in Plant Health Management)

Western flower thrips, Frankliniella occidentalis, is an economically important agriculture pest of hydroponically grown strawberry. Several characteristics predispose western flower thrips to be a successful insect pest in the greenhouse industry. Successful pest management programs of western flower thrips are an integration of several control approaches which include the use of biological agents and chemical applications. This is of particular importance in the production of crops under controlled environments, which provide the proper environment for insect pests such as western flower thrips. Western flower thrips are particularly problematic in hydroponic strawberry production, a fast-growing industry sector. Providing an integrated pest management program to off-season strawberry producers is crucial to this growing industry within the United States. Our first goal was to develop pest population indices based on two sampling methods, sticky card and western flower thrips per flower population counts. Flowers were inspected with the tapping and carbon dioxide flushing method to determine western flower thrips populations per flower. Our second goal was to identify how different production cycles correlated with western flower thrips populations. Data were recorded on number of plants, number of plants in flower, and the number of flowers present during both production cycles. Results indicate that western flower thrips population is well correlated with the number of flowers in the production space. The next step is to find the action threshold based on the damage through the production cycles. Our third goal was to monitor pest and biological control populations. Data were collected on western flower thrips and natural enemy populations with destructive plant sampling and a battery-operated aspirator. Our fourth goal was to determine if red netting is an effective plant protection tool against western flower thrips. We applied red and white nets to plants and exposed the plants to a thrips colony. The results of the experiment led us to theorized that the red netting reflected ambient light produced by the high pressure sodium lamps differently than the white netting, and that effect may be used as a plant protection strategy against thrips. The next step is to obtain reflection measurements with a spectroradiometer.