Forbes scale

Insect

Forbes scale

Quadraspidiotus forbesi (Johnson)

Hemiptera: Sternorrhyncha: Diaspididae

Distribution: Most fruit-growing states and provinces in eastern North America.

Photos

A round or elongated scale with a raised reddish area in the center. Gus Howitt, MSU
A

Round or elongate gray scale with a raised reddish area in the center (A, B), which distinguishes it from the San Jose scale (Quadraspidiotus perniciosus).

Crops Affected: apples, cherries, pears, plums

Damage

Attacks cherry, apple, apricot, pear, plum, and quince. Masses of gray, thin, flaky scales occur on the bark of the trunk and branches, sometimes completely covering it (C). Crawlers make their way to fruits, where their feeding produces small red spots about 3 mm in diameter with a light-colored area in the center.

Management

Spray a delayed dormant oil when buds are showing green tissue but before pink bud. Insecticide applications may be made to control newly hatched crawlers in early summer.