- Author: Neil McRoberts
Dixon Area General situation It has been an up and down start to the year for thrips development. Through February the relatively dry winter, and somewhat warm start to the year in the San Joaquin Valley meant we were running ahead of the 30 year average for degree day accumulation. The last couple of rain events have slowed things down, but we are still ahead of the long-term average. Temperatures in the week ahead are predicted to be in the mid 60's F to mid 70's F, with the chance of further rain in the second half of the week.
Dixon Area Thrips populations and TSWV risk At the moment the first post-winter adults are projected to peak around the end of the week, with the second generation peaking around May 20th. If things warm up significantly those two generations may peak a few days earlier. Currently we don't have any reports of TSWV activity in overwintering hosts and with the very low thrips populations now, the overall risk is low. Our best guess at the moment is that we won't see significant thrips/TSWV activity until the third generation this year, which will be the first one to target, depending on whether TSWV has appeared, but please speak to your local UCCE adviser for more specific advice if you are concerned.
Hollister/Gilroy Area General situation Similar to elsewhere, it has been an up and down start to the year for thrips development. Through February the relatively dry winter, and somewhat warm start to the year in the Pacheco area meant we were running ahead of the 30 year average for degree day accumulation. The last couple of rain events have slowed things down, but we are still ahead of the long-term average. Temperatures in the week ahead are predicted to be in the mid 60's F to low 70's F, with the chance of further rain in the second half of the week.
Hollister/Gilroy Area Thrips populations and TSWV risk The first post-winter adults peaked around the end of the March, with the second generation expected to peak in early May. Assuming things warm up and hit a stable pattern this month we can expect the third generation toward the end of May or first week in June. Currently we don't have any reports of TSWV activity in overwintering hosts and with the very low thrips populations now, the overall risk is low. Our best guess at the moment is that we won't see significant thrips/TSWV activity until the third generation this year, which will be the first one to target, depending on whether TSWV has appeared, but please speak to your local UCCE adviser for more specific advice if you are concerned.