Mature females overwinter, often with eggs already deposited under their wax cover. Eggs hatch in early spring, and the mobile crawlers move to positions on the previous year’s needles, where they then insert their mouthparts and become sessile, remaining at that site for their life. As the nymphs molt they retain the caste skin and incorporate it as part of a protective cover over themselves, creating the distinctive “oyster” shell appearance. After mating the mature female then produces the wax cover and deposits up to 60 eggs beneath it. There may be 2 generations each year.
Heavy infestations can cause yellowing of the needles and premature loss of the needles. Affected plants lose much of their vigor and aesthetic appeal. Pines can tolerate small infestations, but if aesthetics or plant health are a concern dormant or summer oils may be effective in killing the scales, as well as contact insecticides applied when the first instar crawlers are present