Quadraspidiotus perniciosus
Pest description 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. The San Jose scale is found on fruit trees and many ornamentals throughout the U.S., particularly in hot, dry climates. San Jose scale can be differentiated from other scale insects by the scale (shell) that covers the adult females. The San Jose scale is about 0.06 inch in diameter, and hard, gray to black, and cone shaped. The scale has a tiny white knob in the center with a series of grooves or rings around it. Twigs with infested bark are roughened, rather than smooth, and twig death may occur. Often there is a purple halo on the bark around the scale. At high population densities, fruit is infested. Crawlers are flat, yellow, and common in June and again in August to September.
For biology, life history, monitoring and management
See:
Cherry, flowering (Prunus)-San Jose scale
See "Scale insect" in:
Management-chemical control
See Table 1 in: