But Haviland said growers who spray at the first sign of mites might, in fact, be setting themselves up for problems later.

Food source

It is important for some mites to be present in the orchard early season to provide a food source for beneficials including six-spotted thrips, which, if allowed to thrive in the orchard, are an excellent natural biological control for spider mites. Allowing biocontrol organisms to get established, in fact, can reduce the risk of spider mite explosions later in the season.

Products containing abamectin, while inexpensive and effective on mites, are also known to kill six-spotted thrips and should be used cautiously if this predator is present in the orchard. In addition, pyrethroids and other broad-spectrum insecticides should be avoided until hull split unless they are absolutely necessary for leaffooted bug or other sporadic pests when no alternatives exist.

Tree Nut Updates

Monitoring and presence-absence thresholds that account for spider mites and natural predators should be implemented as part of a season-long IPM mite management program. Six-spotted thrips are the most common and effective natural predator of spider mites.

Others include minute pirate bugs, lacewings and predatory mites.