The comstock mealybugs had been occurred at a Muscat of Alexandria’ organic vineyard in Okcheon. They had beenfound in the vines’s trunk since mid-June and moved to cane and leaves since early July, and also had been found ingrape clusters since late-July. The number of comstock mealybug and the grape’s fruit damage in Eco-friendly vineyardswere higher than in conventional culture vineyard. And the marketability of green variety grape was more damaged fromcomstock mealybug than the black variety grape. Toxicities of 8 organic agricultural materials(OAM) were evaluated tocomstock mealybug at the recommended concentration. As a results, Lightyellow sophora and Derris extracts exhibitedstrong insecticidal activity with 100% mortality. When the Lightyellow sophora extract was uniformly distributed on thevine from early-July to mid-July, commercial grapes could be harvested. Therefore, I thought that we can control comstockmealybug by spraying OAM in a timely period.