April 15, 2026 update
General background: Just like last year, we are a little slow getting off the mark with our updates this year. The UC ANR web platform is still giving us issues and we’ll be reporting thrips development here, at least for the start of this season .
Thrips development: The first post winter generation adults peaked around March 17th (about 2 weeks earlier than 2025). Peak egg hatch for generation 2 peaked around March 30th. Generation 2 adults will peak around April 20th. Based on current development rates and projected temperatures, the third generation of adults should peak in late May.
We have had one report of TSWV in a tomato crop already and some yellow sticky cards showing appreciable thrips numbers. Although treatment this early in the season is usually not needed, if you are worried about TSWV, or know that your crops have a history of TSWV damage, contact your UCCE farm advisor for advice about whether an early thrips treatment might be needed. If you are not seeing TSWV damage already, it is unlikely that treatment for thrips will be useful until the third generation at the earliest, but bear in mind that things seem to be running ahead of normal this season.