Eastern Flower Thrips on Strawberries

Source: Purdue Fruit Newsletter 5/19/99

High numbers of Eastern Flower Thrips have been reported on late blooming strawberry varieties in the Bedford area. Growers should scout their plantings closely for this pest. As you may recall, Eastern flower thrips were a serious problem across the Midwest in 1994. Since that time we have not seen serious problems with this pest. However, growers should scout their plantings to avoid the major losses that occurred in 1994.  It is the consensus of the fruit entomologists in the Midwest, after discussions with entomologists from around the country, that 10 thrips per flower is a reasonable threshold. We must admit, however, that this threshold is not based on hard data, but is our best guess. We all agree that it is important that growers not treat during bloom unless they have some evidence that an insecticide spray is needed. Our bee colonies are in serious trouble, so we need to protect them as much as possible. We strongly recommend that growers scout for thrips in their strawberry flowers and confirm that thrips are present before applying insecticides.   Thiodan or Lorsban appear to be the best insecticides for thrips control. See ID-169 Indiana Commercial Small Fruit & Grape Spray Guide for complete information regarding this pest.