Gloomy Scale

Contact: Eric Day, Manager, Insect Identification Laboratory

August 1996

Gloomy Scale

Homoptera: Diaspididae, Melanaspis tenebricosus (Comstock)

Plants Attacked

Primarily red and silver maple; also elm, hackberry, and boxelder.

Description of Damage

The bark becomes roughened and encrusted with scales. Branches and limbs die back and result in a rapid decline in tree vigor, occasionally resulting in the death of trees. Seriously weakened trees are common in Virginia as a result of scale populations, especially red and silver maples.

Identification

The scale cover is circular, dark gray, with a black nipple on dorsum. The underside cover is snowy white. Damaging stage - nymphs and adults.

Life History

Immatures complete development in spring and by early- to mid-June eggs are hatching. These crawlers settle and produce a second brood by late summer to early fall. These immatures overwinter until spring when development is completed. Two-plus generations per year. Overwintering stage - immatures.

Control

Spray with oils during dormant periods. Sprays for crawlers may help, but crawlers emerge over a long period. There is a peak in mid-June, but 2 or 3 sprays at weekly intervals are necessary to obtain only fair control.

Remarks

Very destructive to forest and shade trees.

Visit Virginia Cooperative Extension