LABORATORY AND FIELD EVALUATIONS OF NEONICOTINOID INSECTICIDES AGAINST THE GLASSY-WINGED SHARPSHOOTER

• Author(s): Byrne, Frank; Toscano, Nick; Drake, Ben; Gispert, Carmen; Ishida, Ed; Jiminez, Manuel; Learned, Mac;
• Abstract: Admire and Platinum applications were compared in a Temecula vineyard. In previous trials conducted on both citrus and grapevines, we observed superior rates of uptake with Platinum despite lower application rates. In our most recent trial conducted in a Temecula vineyard, applications of Platinum at 11 fl oz/acre resulted in higher concentrations of active ingredient in the xylem fluid compared with applications of Admire at 16 fl oz/acre. Although peak levels of thiamethoxam declined more rapidly than imidacloprid, effective concentrations of both neonicotinoids persisted within vines during the season to provide adequate protection against glassy-winged sharpshooter (GWSS). In studies conducted in two Coachella Valley vineyards, we found that the size girdling of vines at the time of Admire application did not impact the uptake of imidacloprid. At one vineyard, we did observe distinct differences in the overall levels of imidacloprid present within vines sampled at two distances from the irrigation pumps. Thus, during the course of application, vines nearest the injection source could receive significantly more insecticide than those further away. Admire (32 fl oz/acre) applied to flood-irrigated citrus achieved threshold levels of imidacloprid within five weeks; these levels were then maintained for up to four months. The binding capacity of Coachella vineyard soils was considerably lower compared with Temecula and Napa vineyard soils. In soil column studies, the imidacloprid elution profiles were very similar for Temecula and Napa soils. Dramatic differences in the uptake of imidacloprid following Admire applications in vineyards at these locations can be attributed to differences in irrigation practices.
• Publication Date: Dec 2005
• Journal: 2005 Pierce's Disease Research Symposium