Weather outlook: After further atypical cool, showery weather over the last week or so, the forecast for the next ten days shows a more settled period of dry weather with partial cloud cover and daytime highs increasing towards the mid 90'sF. Thrips population development can be expected to be steady over this period.
Thrips population timings: In our last update on 4/16 we projected Generation 3 adults to peak on May 27th and Generation 4 to peak on June 21st. The period of cool weather has slowed development somewhat, delaying the projected generation times. The projected peak date for Generation 3 is now June 1st, with Generation 4 now projected to peak on June 24th. There are reports of low TSWV incidence in the area. We also detected SW-5 resistance-breaking strains of TSWV earlier in the season, but the overall risk level remains low to moderate at this time. Depending on crop development stage we recommend targeting Generation 4 for any intended thrips treatments if they have not already been made. Later planted crops may still be at early, vulnerable growth stages as Generations 3 and 4 emerge; stay on top of the situation and check in with your UCCE adviser to find out if TSWV is being reported as the season progresses.