Weather outlook The next 10 days will see consistent warm, dry weather in the San Joaquin Valley. Highs in the upper 70's to upper 80's and overnight lows in the mid to low 50's will allow steady thrips development, and we should see numbers starting to build up.
Generation peak timings Generation 3 post winter is likely to peak around May 31st, and generation 4 will peak around June 23rd. If you are concerned about TSWV risk these are the two generations where control will have the biggest impact. Knocking thrips numbers down while the populations are still relatively small and while the crop is still small enough to allow good penetration of sprays is a good tactic. Keeping thrips under control at this stage also allows the crop to grow past the really vulnerable stage before and during flowering before there is much TSWV around and helps to reduce the yield impact if the virus does show up. The UC IPM guidelines for thrips control can be found by following this link. Further advice on treatments is available from your local UCCE adviser.