Calico Scale Management

Purple loosestrife Jamee Hubbard has been studying Calico scale for three years in Dr. Dan Potter’s Turf and Ornamental Laboratory. In that time, she has made several interesting discoveries about this insect. First, unlike most other scales, oils do not seem to be very effective at controlling this pest. This is true of both the summer oils and dormant oils. Jamee said that oils will give some control in the spring when the crawlers first hatch but the rate is low. The best products that she has found are Talstar (and other pyrethroids) and Orthene. Sevin also provides good control but caution needs to be taken when using sevin because it is extremely toxic to bees. Control is easier when the crawlers are small but control measures can be effective until the crawlers move off the leaves in the fall. The key to good control is getting the insecticide to the underside of the leaf where the crawlers are feeding. Calico Scale Management Jamee Hubbard, Ph.D. student, Univ. of Kentucky