Euonymus Scale
Contact: Eric Day, Manager, Insect Identification Laboratory
August 1996
Euonymus Scale
Homoptera: Diaspididae, Unaspis euonymi (Comstock)
Plants Attacked
Euonymus, bittersweet, pachysandra, etc.
Description of Damage
Plants loose vigor and become spindly.
The leaves turn yellow and fall prematurely. Heavy infestations
can kill the plants.
Identification
Females, pear-shaped and dark brown, male scales
are white with yellow cap on one end - easily observable on
plants. All stages damage plants.
Life History
Eggs are laid early in the spring and hatch in
late May or early June. These crawlers settle quickly and
produce a second brood by mid-July. A third brood is produced in
October. There is continuous overlapping of broods, so that, all
stages may be found during favorable conditions. Two to
three-plus generations per year; weather dependent. Overwintering
stage - adult female.
Control
Sprays applied at time of hatch in late May and
repeated in 7-10 days should control crawlers. For heavy
infestations spray in early June, mid July, and early October as
stated above.
Remarks
We still lack a thoroughly effective control. Most
difficult to kill are scales at the base of the plant near the
ground, particularly on vine type of euonymus.
