Tuliptree scale (Toumeyella liriodendri) is a native type of soft scaleinsect that can be difficult to manage as their waxy body covering shields them from predators and certain pesticides. Learn more about scale insect groups and biology on Introduction to Scale Insects.
This is a common pest of tulip poplar, magnolia, and a few other trees and shrubsand can cause stunting and dieback when populations are high.
The crawler emergence period depends on temperature and can vary slightly from year to year. The approximate time to monitor for them is mid-September through October.
They overwinter on the bark as juveniles.
Refer to our general scale management recommendations for both chemical-based and pesticide-free options. When pesticides are warranted, a combination of dormant oil applications and the use of systemic or growth-regulating insecticides is the most effective approach. For large populations, scale suppression may require more than one year of intervention, and professional pesticide applicators will be needed to apply certain treatments. Mature trees should be evaluated by a certified arborist.
The brief crawler emergence period for tuliptree scale means that monitoring and treatment may need to occur in a relatively limited timeframe.
Start monitoring for crawlers right before the expected emergence period. Since weather trends can shift date ranges, a more reliable prediction of timing can be made using Growing Degree Days and Plant Phenological Indicators.
Below is a refined estimate of egg hatch and the beginning of crawler emergence:
3519 degree days
After the peak flowering of the Seven-son Flower (Heptacodium miconioides)
Adapted from: Davidson, J.A. and M.J. Raupp. 2014. Managing Insects and Mites on Woody Plants: an IPM approach. Third Edition, revised. Tree Care Industry Assoc. Londonderry, NH. 175pp. Illus. andthe Pest Predictive Calendar, also the Scale Crawler Emergence Period chart compiled by Stanton Gill, Suzanne Klick, and Sarah Kenney.
Complied by Miri Talabac, Horticulturalist & Coordinator, HGIC. 2022