Areawide mating disruption for vine mealybug in California vineyards. (October 2021) - Hogg, Brian N.
Abstract: The mealybug, Planococcus ficus (Signoret), is one of the more damaging vineyard pests and an important vector of Grapevine leafroll-associated viruses. Pheromone-mediated mating disruption is a commercially available and environmentally sustainable control tool for P. ficus . Here we report on a three-year areawide study of P. ficus mating disruption in Napa County, California, where pheromone dispensers were deployed across large (53–66 ha) multi-owner sites that were paired with sites that did not receive pheromone. Male P. ficus captures in pheromone traps were correlated with mealybug numbers and crop damage, and were useful in identifying 'hotspots' to be targeted with insecticide applications for areawide control. Trap catches at mating disruption sites were far lower than untreated sites, although mealybugs were still present at mating disruption sites. Evidence indicated that mating disruption reduced P. ficus density and spread, particularly in areas with low initial mealybug densities. In the third year, areawide mating disruption was discontinued at the former mating disruption sites and, as evidence of its impact, P. ficus trap captures increased. These results suggest that mating disruption and well-timed, effective insecticide applications play complementary roles, and that monitoring the areawide distribution of pests is a critical component of programs for controlling P. ficus . Highlights: Pheromone traps were useful in identifying 'hotspots' of the mealybug Planococcus ficus . Mating disruption appeared to limit Pl. ficus density and spread over large vineyard areas. Effects of mating disruption were most pronounced in areas with low mealybug densities. Pl. ficus trap captures increased at most sites after mating disruption was discontinued. Mating disruption and insecticides likely play complementary roles in Pl. ficus control.