CHAPTER 33 – Biological Control of Insects and Mites on Grapes

This chapter reviews the biological control of insects and mites in various grape-growing regions of the world, with emphasis on California. In California Erythroneura elegantula Osborn, grape leafhopper is the most common pest of grapes. Economic damage is caused by leaf chlorophyll reduction, vine defoliation, marring of the surface of table grapes with excrement, and the leafhoppers annoying pickers at harvest. In California two mealybug species are known to infest vineyards. Pseudococcus maritimus , the grape mealybug, is primarily a pest of table grape cultivars whose bunches make contact with vine bark and become infested. The second species, Pseudococcus affinis , the obscure mealybug, has been recorded on a wide number of hosts and is recently found causing severe damage in unsprayed vineyards in San Luis Obispo County, on California's central south coast. In Chile, the grape quality can be affected by copious amounts of honeydew produced by Parthenolecanium persicae . The natural enemies play an important role in maintaining populations below economic levels but the principal enemies are two encrytid wasps, Coccophagus caridei and Metaphycus flavus .