Mealybugs present in vineyards of Colonia Caroya, Córdoba, Argentina. Incidence on the crop and effect on must quality

Abstract

An increase in mealybug populations has been observed in vineyards of Colonia Caroya, Córdoba, since 2001-2002. The aim of this work was to determine the species present, their incidence on vineyards in the area and their effects on must quality. Species were identified by collecting plant material of red and white grape varieties; incidence and intensity of the most abundant species was quantified in 15 vineyards in 2010 and 2011, and the effect of mealybugs on the must quality of the varieties Chardonnay, Merlot and Pinot noir was determined. Two Pseudococcidae species were identified: Planococcus ficus (Signoret) and Pseudococcus viburni (Signoret), which affect clusters, leaves, buds, vine shoots, and stems, and one Coccidae species, Parthenolecanium persicae (Fabricius) mainly affecting leaves, vine shoots and stems. The most abundant species was P. ficus, with an incidence in vineyards of 73% in 2010 and 87% in 2011. During that period, incidence in plants varied from 17 to 28% and the percentage of infested grape clusters increased with increasing percentage of infested plants. In clusters with more than 50% of rachis affected, the deterioration of some quality indices of must is observed.