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 adults |
Field observations
I was recently in a tomato field west of Woodland that was planted at the end of March, with a greater incidence of TSWV than I’ve seen so far this year (still likely less than 1%, but noticeable given the severity of the symptoms; Figure 1). I have been hearing from others as well that they are noticing more TSWV after last week’s high winds. This would make sense, given the observed increase in thrips numbers. Again, if you are seeing active spread in a field, the next few weeks (3rd and 4th generations of thrips) are a good time to spray.
Figure 1. Several neighboring tomato plants with severe TSWV symptoms (stunting, yellowing, leaf necrosis).