European Fruit Lecanium: Parthenolecanium corni
Homoptera (Heteroptera): Coccidae
Identification
• Adults are dark brown, rounded disks that are about
1/8" in diameter. (a) Nymphs are smaller. (b)
• Cottony maple scale produces a 1/4" diameter white, popcornlike egg
case in June. (c)
Damage
• Both scales suck sap and create large amounts of sticky saplike honeydew
on which grows a black sooty mold. Heavily attacked trees lose some leaves
and branches.
• Cottony maple scale heavily attacks silver maple and is also found
on honey-locust, walnut, linden, and sumac.
• European fruit lecanium is found on crabapple, maple, hackberry,
and many other trees.
Management
• Cottony maple scale is controlled by twice-stabbed lady beetles.
The beetle larvae look similar to the scale egg sacs but move slowly; the
adults are about 1/8" in diameter and black with two red spots on the back.
(d)
• European fruit lecanium become very numerous when the host tree is
under stress. They become less numerous when the tree regains its health.
• Both scales are controlled with dormant oil spray.