2023 Thrips Organophosphate Resistance Status

For the last several years, we have sent tobacco thrips population to the University of Tennessee for organophosphate bioassay resistance screening. To date, we have the results for three populations (Stoneville, MS; Glendora, MS; Sidon, MS).  Populations seem to be highly resistant to Orthene (40% control), which is consistent with what we have been seeing in our field trials in addition to field calls. Bidrin, however, seems to be more inconsistent based on location. In some areas, people have seen decent control, while others haven’t. These bioassay results would suggest the same inconsistent control pattern (42-82% control). Across the midsouth, Orthene has continued to provide unacceptable control. Additionally, there have been a number of calls this year suggesting that Intrepid Edge has resulted in an insecticide failure. According to our field trials and lab bioassays, this does not appear to be the case. Oftentimes, adult tobacco thrips recolonization can appear to be an insecticide failure. However, these are two very different things. In our lab bioassay results, Radiant (the component of Intrepid Edge that controls thrips) consistently provided 100% control. In order to get the best results out of Intrepid Edge, it is important to ensure that you are incorporating a surfactant, using proper spray tips that deliver fine droplets, and applying a higher GPA (10+).