immatures may also overwinter (/94). In Maryland, first instars are present from 
late April or early May to late June and early or mid-July to October (485). In 
Massachusetts first instars are present in early June and August. In Ohio they are 
present from May through June and again in late July through August (689). This 
species may be found on the stems, leaves, or fruit of its host. The euonymus scale 
can build to such heavy populations that it may cover much of the surface area of a 
particular host. Under such circumstances the plant will become white with male 
covers (fig. 39). Upper surfaces of leaves become spotted with yellow areas where 
scales are feeding on the undersurface. Heavily infested plants may lose many of 
their leaves and become leggy in appearance. Natural enemies include at least seven 
species of parasitic wasps, one species of lady beetle, a green lacewing, and two 
mites. None of these natural enemies has been reported as an effective biological 
control agent. 
F-519580 
Figure 39.—The euonymus scale, Unaspis euonymi, on 
euonymus. 
122 
