Seasonal abundance and distribution of Planococcus ficus on grape vine in Sardinia

During 2006-2007, the seasonal spatial distribution of Planococcus ficus throughout the vine was studied in a “Tendone system” trained vineyard, situated in the North of Sardinia (Italy). Male flights were monitored by pheromone-baited traps, whereas eggs, crawlers, nymphs and females abundance was estimated by counting on trunk, canes, spurs, leaves and bunches. Vine mealybug developed throughout all the year in cryptic location under the bark of trunk and arms, overwintering principally as fecundated female, or eggs in ovisacs. In April, the majority of crawlers were found under the bark and, after bud break, also around the base of new shoots. Females of this generation were detected in June, and crawlers of the second generation moved toward basal leaves. Females of this generation peaked at the end of July, and the crawlers of the third generation colonised grape bunches in late July-August. The maximum female density was recorded in October and, after the leaf quality deterioration, the majority of mealybugs moved back under the bark. Males were captured by pheromone traps from May to December and their population density showed three peaks in June, late July and September-October, when the highest female density was recorded.