Mite pressure remains relatively low in Kern County, but that could change if hot temperatures continue to prevail, which is standard at this point in the season.

“Mite activity in Kern County table grapes has been spotty,” says David Haviland, Kern County farm advisor. “We have seen a small number of isolated fields where Pacific mites have already come in and done major damage. In other cases, Willamettes are around and starting to build. Overall, however, mites seem to be running a normal course. Many fields are still without a miticide, while many others have had only one miticide treatment.”

With a well-stocked miticide arsenal available, PCAs and growers are testing the waters to see what works best under specific circumstances. With so many chemistries now on the market, the concept of preserving beneficials — especially early in the season — has become more feasible.

“Most are still learning which are soft and which are not,” Haviland says. “Generally speaking, all of the new miticides are very soft on predatory insects. As for predatory mites, Zeal and Fujimite are the most toxic. Zeal causes egg sterilization of predatory mites, and Fujimite kills them by direct contact. Other miticides such as Envidor, Oberon, Agri-Mek, and Onager are somewhere in the middle when it comes to toxicity to predatory mites, whereas Acramite is one of the safest.”