Thrips/TSWV status in Yolo & Colusa
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2025 3rd Report-- April 30

Thrips population


Thrips are currently in Generation 2, with adults predicted to peak in the second week of May. Spring temperatures remain similar to long-term normals, and population predictions have not changed much from last update.

Table 03_20250430



Thrips and TSWV monitoring


We have started to monitor thrips coming into tomato and pepper fields in historic TSWV hotspots in Yolo and Solano counties. This is done by placing yellow sticky cards on a field edge, with the sticky side facing away from the field and towards an area from which thrips are predicted to move into the field. These include exposed natural areas, weedy orchards, and wheat fields. As expected, at the moment we are seeing the highest numbers in fields near open natural areas, where large numbers are blown in on the wind. We have not yet found any TSWV infections on the young tomato or pepper plants, suggesting that the viral load is still relatively low. 
 

Yellow sticky card field placement