Toumeyella liriodendri (Gmelin). Tuliptree scale is a large, 1/3 inch diameter, soft scale that infests tuliptree or yellow poplar, magnolia, and occasionally linden. Female covers can vary from gray to pink mottled with black. Large numbers of this hemispherically- shaped scale can give infested branches a bumpy or warty appearance and may cause branch dieback. Tuliptree scales produce large amounts of honeydew so leaves are often shiny or may be covered with sooty mold.
There is one generation of the tuliptree scale each year. They spend the winter in an immature stage with females maturing during late summer and laying eggs that hatch in August.
Scale control can be challenging and may need to be repeated over several seasons. This is due in part to the protection from contact insecticides provided by the waxy coverings over immobile, mature scales. Proper timing of insecticide applications is a major key to success. Applications must target newly hatched scale crawlers which are active in June and July. Crawlers are very susceptible to control measures as they move over plant surfaces to find a feeding spot. Once settled on the plant, they begin to secrete a covering and are protected by it.
