Pest pressure is beginning to build in California’s Central Valley, while disease has been mostly light this season.

“Mealybugs are bad,” says Devin Carroll, PCA, Advanced Agricultural Services in Fresno, Calif. “Some of my clients used a systemic in May for thrips control this year. I suspect it suppressed the predatory midge maggot. Consequently biocontrol has been poor for grape mealybug. Vine mealybug, of course, is even worse.”

Oddly, the heat that hit the Central Valley in recent weeks has not yet triggered mites everywhere, but it has reduced powdery mildew pressure.

“Mites are not as bad as they have been in recent years,” Carroll says. “As for mildew, the weather has cooperated by turning hot.”