Research by UC integrated pest management entomologist Walt Bentley shows that the use of the systemic insecticide Admire (imidicloprid) on grape vines infested with the newly introduced vine mealybug can reduce pest numbers to very low levels.
"Damage in treated areas was found on less than 3 percent of the clusters. In the untreated areas, 20 percent of clusters were damaged," Bentley said. "It looks pretty effective." However, the pesticide is expensive, running from $60 to $90 per acre, considerably more than farmers typically spend on raisin grape pest control. Also, applying Admire at those levels could quickly lead to pesticide resistance, Bentley said.