Field corn plants grown with seasonal irrigations of 70 cb or less soil moisture tension, applied every furrow, supported fewer mites (Oligonychus pratensis(Banks) andTetranychus cinnabarinus(Boisduval)) and showed lower levels of plant stress than plants in plots kept dry (200 cb) at some time during the growing season. Mite densities remained low before tassel and began increasing rapidly prior to soft dough. Prolonged rain and thunder-storms at tassel caused reduced mite density. It was concluded that rain and/or instrument controlled irrigations of ≤ 50 cb can limit the growth and severity of spider mite populations on corn.