Mechanically-applied wax matrix (SPLAT-GBM) for mating disruption of grape berry moth (Lepidoptera: Tortricidae)
A paraffin wax formulation releasing pheromone for mating disruption of insects was tested during 2005 and 2006 in Vitis labrusca vineyards infested by grape berry moth, Paralobesia viteana (Lepidoptera: Tortricidae). In early May of each year, 1-ml droplets of SPLAT-GBM™ wax containing 3% sex pheromone of P. viteana were applied to every wooden post at a rate of 400/ha in replicated 1.3-ha plots. Moth captures in sex pheromone baited traps placed at the vineyard borders and interiors revealed significant disruption of male moth captures in treated plots, with activity of one application lasting over 10 weeks during both years. Treatment with SPLAT-GBM™ did not affect the proportion of clusters infested until the end of the second growing season, when infestation was 27% lower in the treated plots than in the control plots. Comparisons of moth captures in traps placed inside 15.2 × 16.5 m vine plots that were untreated or received varying densities of 0.2-ml wax drops or Isomate-GBM hand-tied dispensers at the recommended rate of 450/ha indicated that orientational disruption increased with droplet density. Similar numbers of moths were captured in plots that received 10 or 30 drops per vine as were trapped in plots with twist ties spaced at 0.4 per vine. Moth captures in monitoring traps baited with increasing sizes of wax droplets (0.2, 0.5, or 1-ml drops) or red septa containing P. viteana sex pheromone suggest decreasing ability of male moths to reach traps with increasing pheromone loading. This study indicates that wax-deployed pheromone can reduce crop infestation by P. viteana after 2 years of deployment, and that the increasing of pheromone release by using application of greater droplet densities or by using larger droplets will improve the level of disruption achieved.