University of Illinois Extension
University of Illinois Extension - Selecting Trees for Your Home
Magnolia Scale
Neolecanium cornuparvum
Magnolia scale
Severity: 3 out of 5
Frequency: 2 out of 5
Symptoms: This scale produces honeydew in large quantities. Sooty mold (a fungus) grows on the honeydew. This causes the plant to turn blackish in appearance. In addition to the feeding damage by the scale, the sooty mold, when it becomes dense enough, causes the leaves to die early.
Cycle: The scale will over winter as a first-instar nymph (look like immature adults). The nymphs continue to develop the following spring. The nymphs secrete a powdery white wax over their body. In northern Illinois, the adult female produces live young.
Management: In the first nymph stage is when the scale is most susceptible to control. This occurs in late September to early October in Northern Illinois. Or treat in the spring when buds are opening. Insecticides need to be applied when insect is in the crawler stage.
Associated trees: