Improving vine mealybug controls through adjuvant addition in major grape growing regions of California

The vine mealybug (Planococcus ficus) is one of the premier pests threatening the California grape industry. The systemic insecticide Movento (Bayer Crop Science) is an effective treatment against the vine mealybug. Movento's efficacy depends on the conversion of its active ingredient, spirotetramat, to its enol form, spirotetramat-enol. The conversion occurs naturally in the leaf, so proper spray coverage and leaf uptake are crucial to ensure its effectiveness. The purpose of this study was to determine the uptake of and conversion of spirotetramat to spirotetramat-enol with the addition of different classes of adjuvants. Further, the study was replicated in prominent grape growing regions of California including, Napa Valley, Sacramento Valley, San Joaquin Valley, and the Central Coast region. Analysis via High-Performance Liquid Chromatography (HPLC) was used to determine the presence and concentration of spirotetramat and spirotetramat-enol in vine leaf samples.