How to Manage Western Flower Thrips in Peak Season

Rick Yates

Many growers enter each season with swords drawn, anticipating another fight to the finish with Western flower thrips (WFT). Rampaging thrips can blaze a devastating trail of scarred blooms and deformed leaves, as well as spread tospoviruses.

GGSPro remains strong proponents of biological control for insect and mite pests, including thrips. However, this time of year is no time to begin a biological control program: Thrips are already active and reproductive rates are very high.

For that reason, our focus today is on pesticides for thrips control. Long before you plan for your next spring crop, you can consult with your supplier about an integrated pest management program that includes scouting, exclusion, sanitation, rotating pesticides and BCAs.

Thrips have a well-earned reputation for developing resistance to pesticides. Practicing a sound rotation strategy is key to slowing the progression of pesticide resistance. We work closely with many growers regarding pest control programs, gaining continuous and valuable insight into which products are working well and how best to utilize them. The products and application strategies outlined in Tables 1 and 2 are currently among the most successful for thrips control.

In addition to efficacy, many factors may influence product selection, including rotational planning, bee safety, compatibility with BCAs, plant and bloom safety, label requirements for edible crops, and more. Contact your supplier for recommendations tailored to your unique situation and needs.

It is the applicator’s responsibility to read and follow all pesticide label instructions. Labels can and do change without notice. Not all of the products mentioned in this article are registered for use in all states. Some pesticides are restricted-use in some states or regions and not others. Contact your supplier or your state’s Department of Agriculture to verify registration status. Pesticides other than those mentioned may be safe and effective. GT

Rick Yates is GGSPro Technical Support Manager for Griffin. He can be reached at