In the last couple issues of Clemson Entomologist Jeremy Greene’s Cotton/Soybean Insect Newsletter, Dr. Greene mentions the Thrips Infestation Predictor (TIP) tool. This tool predicts the thrips pressure of cotton based on planting date. The chart below is from the TIP website (http://climate.ncsu.edu/cottonthripsrisk/) with Dillon, SC selected for the location.
The chart is predicting that cotton planted in early May will see the highest thrips pressure this season. We have a lot of cotton planted in early May and from the looks of it, this chart predicted the thrips pressure accurately. A lot of that early May planted cotton is showing thrips damage, some of it pretty severe.
Some fields could benefit from a foliar insecticide treatment, but before making any decisions to do so, take a look at the section on thrips in the SC Pest Management Handbook (pg. 109-110). According to the handbook, the best time to make an application is before the second true leaf has unfolded. We do have a lot of cotton that fits that description. Once cotton reaches the four-leaf stage, there’s not much benefit to making an application. The plants are big enough that they can tolerate some feeding pressure.
Get out there and scout and be aware of whats going on in each field. If you’d like help scouting or to you’d like to receive Jeremy Greene’s Cotton/Soybean Insect Newsletters, please contact your local Clemson Extension agent.