Novel dispensers and variable deployment rates for mating disruption of a vineyard mealybug, Planococcusficus

Abstract

The vine mealybug, Planococcus ficus, is a global pest of grapes, leading to lower yields and transmission of damaging viral pathogens. Insecticides are the predominate method of P. ficus management, but some pesticide options have been lost in many of the world's vineyard regions and other economically viable options are now critically needed. Mating disruption is commercially available for P. ficus, however recommended deployment rates can be costly. To reduce costs, the effectiveness of lower dispenser deployment rates should be fully explored. In 2018–2019, we tested a novel high-density passive dispenser at 494 dispensers per ha. In 2020–2022 variable rates of the high-density dispenser were tested and a novel meso passive dispenser at variable rates was also tested in separate trails. An insecticide was applied to all treatments in 2018–2019 and to two of four blocks in 2020. All trials occurred in central California, US. The high-density dispensers (494 dispensers per ha) reduced male P. ficus captures and crop damage in both years. High-density dispensers at variable deployment rates (62–370 dispensers per ha) and meso dispensers (62–270 dispensers per ha) reduced P. ficus trap captures, with increasing dispenser density decreasing trap captures. Crop damage, amount of P. ficus per grape cluster, was significantly reduced only in the second year of the meso trial. Mating disruption is an effective method of suppressing P. ficus and current recommend rates could be lowered, which would reduce costs for growers and increase adoption of this sustainable tactic.