Adult females are about 0.03 inch long. Active summer females are greenish or pale yellow with large dark spots on each side of the body. The Pacific mite may also have a second pair of spots near the posterior end of the body, which help distinguish it from the twospotted mite. Females can complete a generation in as little as 10 days during the hot part of summer. There may be from 8 to 18 generations per year depending on temperature.
Eggs are spherical and almost translucent when first laid.
They are generally deposited on the underside of leaves. As heavy populations build up eggs may be deposited on both surfaces. Twospotted mites generally feed on the lower leaf surface, but Pacific mites may be found on both leaf surfaces. If defoliation happens early in the season, fruit fails to size properly and limbs and fruit may be exposed to sunburn. Mite buildups are encouraged by hot, dry, and dusty conditions, so keep orchards well irrigated, and treat orchard roads, if necessary, to keep dust to a minimum.