Under heavy population pressure, stems and nuts begin to shrivel. Damaged nuts remain on the tree and can provide an overwintering source for navel orangeworm. Close examination will reveal citrus flat mite. They are most easily observed around shriveled and damaged areas. No precise guidelines are available to determine the need for treatment.
Populations can be spotty, and in following years become more widespread in the orchard.
Initiate treatments when flat mite populations in nut clusters can be easily detected, but before nut shriveling. Use higher rates by air. Check label to confirm product is labeled for pistachio. May be applied by ground or air. Check label to confirm product is labeled for pistachio.