The Japanese maple scale (JMS), Lopholeucaspis japonica Cockerell, is an insect pest of Japanese maples and several other ornamental tree species. This insect sucks out plant juices using its piercing and sucking mouthparts. Because JMS, similar to other armored scales, does not directly feed on the phloem vessels of the host tree, the insect does not ingest excessive amounts of sugars to excrete them as honeydew. Instead, JMS secretes a detached waxy shell that covers the body. Adult male JMS are winged, leave their waxy shell, and are not common. The wingless females are 2 millimeters long and remain under their waxy shell or cover. Female and nymph JMS are lavender-colored and found beneath their off-white, oyster-shell-shaped covers. Females primarily aggregate on tree bark, at the base of branches, and in the cracks and crevices on the bark, although they are occasionally found on the leaves. They often blend in with the colors and patterns of tree bark and are challenging to detect. JMS-infested trees in the landscape reduce the value of the property. In the nursery, JMS infestation affects the marketability of the trees. Branch dieback symptoms appear when the trees are heavily infested.
Status and Revision History
Published on Nov 20, 2019