Thrips/TSWV status in Yolo & Colusa

2026 5th Report—Warm temperatures over the past week have accelerated thrips generations slightly from last update. The fourth generation will be hatching soon. This is a good window to spray, particularly in more recently planted fields and if you are seeing active spread.  After fruits have begun to…

2026 4th Report—Thrips generation predictions have not changed much since last update. We are currently in the peak of the third generation, going into the fourth. Generation Predicted date Gen 3 peak adults 5/27 Gen 4 egg hatch 6/10 Gen 4 peak adults 6/21 Gen 5 peak adults 7/14 Current generation Gen 3…

Tomato planting is wrapping up, and some early-planted fields are approaching canopy closure. Mid-to late-May has been on the warm side of normal, and the estimates for upcoming thrips generations have been moved slightly forward. Generation Predicted date Gen 3 peak adults 5/24 Gen 4 egg hatch 6/1 Gen…

2026 3rd Report—Although April and May temperatures have generally been on the cool side of normal, the hot March means that thrips generations are still ahead of normal. Generation 2 adults are feeding and laying their eggs, with generation 3 peak egg hatch predicted in a few days. Generation Predicted…

After the record heat in March, April has cooled to more normal temperatures. Thrips generation predictions have not changed much since last update. We’re approaching the peak of the second generation; adults are feeding and laying their eggs. The third generation is currently predicted to peak around the…