Origin:
Native to North America, and found throughout the country and Canada. It attacks a wide variety of pines, spruces, and cypress species.
Biology:
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.
Identification:
Mature females are about 3 mm long, very flat, and with an elongate oyster-shell shape that is pointed at one end and widened at the other. The scale is white but with an orange tip that is caused by the shed skins of the immature stages.
Characteristicts Important to Control:
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
