EVALUATION OF HERCON LAMINATED DISPENSERS BAITED WITH Z,Z-3,13-OCTADECADIEN-l OL ACETATE FOR SUPPRESSION OF THE GRAPE ROOT BORER, VITACEA POLISTIFORMIS (HARRIS), (LEPIDOPTERA: SESIIDAE), POPULATIONS IN GRAPES1

Z,Z-3,13-Octadecadien-l ol acetate (hereafter called Z,Z-ODDA), the major pheromone component of the peachtree borer, Synanthedon exitiosa (Say), was evaluated in grape vineyards in Arkansas and North Carolina as a mating disruptant and population suppressant of the grape root borer (GRB), Vitacea polistiformis (Harris). An analysis of covariance was performed using the presence and absence of pheromone as the treatment grouping and the initial 1981 GRB emergence data from each plot as the covariate. The adjusted (least squares) mean number of GRB pupal skins per pheromone-treated plot in 1983 was significantly less (P = 0.088) than the number of skins counted in the check plots, indicating that the GRB density decreased two fold faster in the pheromone-treated plots than in the check plots. Field observations showed that the attractancy and eventual mating with calling GRB females by conspecific males was reduced to nearly zero in the plots air-permeated with Z,Z-ODDA. The GRB population decreased in all untreated plots except one where it actually increased. The decreases were attributed to low rainfall throughout the GRB egg hatch period whereas the increase in one plot was attributed to more rainfall and use of overhead irrigation.