Both Treatments and Natural Defenses Show Results for Managing Vine Mealybug
A vine mealybug population can be difficult to treat because they can be all over the plant and be in many different stages of growth. Cooperative Extension Specialist Kent Daane says there are a few options available for management and timing is key for those applications.
Daane added growers can purchase natural defenses, for integrated pest management systems and organic growers, and one in particular shows decent results. The most successful parasite for control is known as Anagyrus pseudococci.
More on Treating Vine Mealybug
From UC IPM: If vine mealybug is found in a vineyard, treatment is recommended. However, the level of treatment varies greatly depending on the region, type of grape, and harvest date:
•Coastal regions only have two to three generations of vine mealybug per year, compared to five to seven in the lower San Joaquin Valley.
•Table grapes have no allowance for mealybugs in the cluster, while wine grapes can tolerate low levels.
•Harvest dates vary widely in table grapes. Fruit from a Flame Seedless vineyard, harvested on the first of July, is less susceptible to damage than fruit in a neighboring Crimson Seedless vineyard, which might be harvested in October.
Due to the complexity of these and other factors, such as biological control, decisions about the level of mealybug control need to be made on a vineyard-by-vineyard basis.
In vineyards with low mealybug pressure, a single insecticide application in the spring or at bloom is often sufficient for season-long mealybug control. Effective control in heavily infested table grape vineyards, planted to a late-harvested variety, may require three or more treatments. Read more from the UC IPM website.