Biology and management of chili thrips in strawberry

Chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae)  is an important early-season pest of Florida strawberry. Chilli thrips adults immigrate from nearby crops and vegetation as soon as overhead sprinkle irrigation is terminated in the strawberry fields. Adults oviposit eggs on the newest leaves and both adults and larvae feed on leaves causing bronzing and darkening injury to leaves. The short-range movement of chilli thrips is slow between strawberry plants and both adults and larvae remain aggregated in initially infested plants for at least two weeks, providing a significant window for management actions before plant and crop loss becomes severe. Actively growing young strawberry plants appear to tolerate slight feeding injury caused by an initial two adults or larvae per trifoliate. Thus, Insecticides can be delayed for two weeks if the chilli thrips population is below an action threshold of two adults or larvae per trifoliate. A decision to apply insecticide can now be based on a sequential sampling plan. To make a decision, a minimum of four and a maximum of 27 sampling units (one sampling unit = 10 strawberry trifoliates) are needed. Spinetoram is the most effective and flupyradifurone, acetamiprid, and cyantraniliprole are fairly effective insecticides against chilli thrips. It is recommended to follow the label instructions and rotate insecticides of different modes of action.