We are beginning to see thrips numbers and injury increase in trials on the research station in Suffolk. Many folks are making decisions this week about whether or not a foliar application is needed, and if so, what to spray.

The first thing to consider in cotton is the growth stage. You are most likely to get an economic return on a foliar application made at the early first true leaf stage. Applications made beyond this stage usually have diminishing return on that investment. In many of our trials planted in late may, we have progressed to the second true leaf stage, and third true leaf in some cases.

Last year, we found tobacco thrips in Virginia with reduced susceptibility to acephate (~75-80% mortality). This year we are continuing to monitor using lab assays and field trials. Results of lab screenings are still to come, but in our earliest field tests on station, acephate (at 8 oz/ac) has provided an acceptable level of control. This is one location and one planting date. Milage will vary by location, planting date, and field conditions. If you decide to make a foliar application of acephate, it will be important to carefully monitor after the fact to ensure an acceptable level of control. The alternative option which provides excellent control is Hemi SC (2.5 – 3.0 oz/ac). This product needs to be applied with a non-ionic surfactant or with an herbicide that already has a surfactant to provide good control.

In 2025, the percentage of western flower thrips in the population was high (70%-80% in many fields). This year, we have seen the opposite so far with about 70% tobacco thrips in our tests on station. Western flower thrips have always been more difficult to control with acephate, so a lower percentage of this species makes acpehate a more viable option. Again, the species composition can vary by location and field conditions.

As always, please contact me with any questions you may have.

Cell: 757-621-8804, Email: btim2@vt.edu