Monitor infested trees regularly to determine when crawlers have hatched. Infested trees can be treated with a registered insecticide during the active crawler stage. Treat only infested trees, as pine tortoise scale populations do not spread rapidly. Spot-treating only infested trees will help preserve populations of natural enemies such as parasitic wasps. Consider using insecticidal soaps, horticultural oils, superior oil or other paraffinic oils in late fall or early spring to control overwintering female scales.
Good coverage is essential if soaps or dormant oils are used.
Soaps and oils will not harm beneficial insect predators such as ladybird beetles. Contact your county MSU-Extension office for information on appropriate registered insecticides. Douglas fir and spruce species may also be infested. Biology Adult female scales are easily recognizable and are the stage commonly seen on Christmas trees. Eggs overwinter under the waxy white exoskeleton of the dead adult female.