University of Illinois Extension

University of Illinois Extension

Hort Answers

Insect Damage

Euonymus Scale
Unaspis euonymi

Euonymous scale
Euonymous scale
3 (1 = rare 5 = annual)
4.5 (1 = very little damage 5 = plants killed)
This scale infest euonymus including winter creeper, vining, and shrub euonymous.

Plants Affected
Euonymus scale females are brown, oystershell-shaped,about 1/8 inch long, and most common on twigs and branches. Males are white, elongate, about 1/8 inch long, and numerous on both leaves and branches. The scale causes the foliage to develop yellowish green spots. Heavy infestation results in early foliage drop and often stems are killed.

Life Cycle
Females over winter and lay eggs in the spring. The eggs hatch about early June in Northern Illinois. Crawlers emerge and move onto new growth or can be blown by wind to other plants. There is one generation per year.

Severe pruning can sometimes elinate or severely reduce infestations. Insecticides can also be used. Treat when catalpa trees are in early bloom.

Related Resources
Home, Yard & Garden Pest Guide
Illinois Commercial Landscape and Turfgrass Pest Management Handbook
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic