May 23, 2025 Update

General Situation: Daily high temperatures will be sitting between the mid 80s and 100F over the next 10 days.  These are good conditions for thrips development, but sustained highs close to 100F may slow population growth down a little.

Thrips development: Generation 3 adults will reach their peak numbers around June 2nd.  Generation 4 will be developing on plants during the first 3 weeks of June, reaching peak adults around June 25th.  For most crops these two generations will present the highest risk of TSWV spreading and causing yield loss.  Focusing thrips treatments into the next 4-6 week window will help keep TSWV damage to a minimum.

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May 2, 2025 update

General Situation: Daily high temperatures will be swinging between the low 70s and low 90s F over the next 10 days.  These are ideal conditions for thrips development.

Thrips development: Generation 2 adults are peaking right now.  Generation 3 will be developing on plants this month, and reaching peak adult numbers around June 3rd.  Generation 4 will be developing on plants during June, reaching peak adults around June 27th.  For most crops these two generations will present the highest risk of TSWV spreading and causing yield loss.  Focusing thrips treatments into the next 8-9 week window will help keep TSWV damage to a minimum.

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April 21, 2025 update

General background: We are a little slow getting off the mark with our updates this year.  The UC ANR web platform was changed in the last month and we're having some issues migrating the old website and blogs over to the new platform.  In the meantime we're using this web hosting platform.

Thrips development: The first post winter generation adults peaked around the end of March.  Peak egg hatch for generation 2 probably almost a week ago (4/16). Generation 2 adults will peak during the first week of May.  Unless there is evidence of TSWV attacking crops this early, it is unlikely that treatment for thrips will be useful at this time.

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April 15, 2025 update

General background: We are a little slow getting off the mark with our updates this year.  Also, the UC ANR web platform was changed in the last couple of weeks and we're having some issues migrating the old website over to the new platform.  In the meantime we're using this temporary web hosting platform.

Thrips development: The first post winter generation adults peaked around the end of March.  We're anticipating peak egg hatch for generation 2 in the next few days, with generation 2 adults peaking around the last week of April.  Unless there is evidence of TSWV attacking crops this early, it is unlikely that treatment for thrips will be useful at this time.