Oak (Quercus)-Pit scale

Asterolecaniidae including Golden oak scale (Asterodiaspis variolosa)

Description, biology and damage Scale insects are small (less than 0.125 inch in length) soft insects that live beneath waxy scales. These insects are often identified by the shape and size of their scales, the description of adult males and females, immature crawler stage, color of eggs, and host plant preferences. Adult pit scale insects are covered with a hard scale and are about 0.06 inch in diameter. They may be brown, gold, or greenish. They feed on twigs and small branches, with young wood most infested. Pit scale feeding causes the tissue of the twig to swell around the insect, so the scale only appears to be in a pit on the bark. Numerous scales on a twig cause it to appear roughened. Severe infestations cause twig dieback. Heavy infestations of pit scales combined with drought stress or anthracnose (a fungal disease) can result in severe weakening or death of trees.

For biology, life history, monitoring and management

See "Scale insect" in:

Management-chemical control

See Table 1 in: