Natural predators of pest insects and mites are also very sensitive to pyrethroids, and can be knocked out of the system by repeated applications. The best way to avoid these potential problems is to apply Danitol only once or twice, preferably early in the season before predator populations start to develop. Insect management programs should be planned to get control of grape berry moth and leafhoppers early in the season before they become a problem and threaten the photosynthesis of leaves and the quality of the grapes later in the year. Remember that like most broad-spectrum insecticides, any new foliage that grows after application of this product will not be protected from insect damage. Another new product registered for grapes this year is the sprayable GBM pheromone for mating disruption of grape berry moth, and can be an effective tool in vineyards with low to moderate GBM pressure.
Pheromones work very differently from other insecticides.
They reduce pest populations by 'jamming' the communication between male and female moths, so that they cannot find each other, and then do not mate. It's like applying a 'fog' to the vineyard, and the male moth can no longer see the female's 'smoke signals'. When mating is reduced, fewer eggs are laid, and fewer berry moth larvae are in the fruit. This product must be applied against a generation of GBM immediately when adult moths are caught in pheromone traps, so regular trap monitoring will help with this decision. It is better to be a little early with this product than one day late.