- San Jose scale
/san" hoh zay'/a scale insect, Aspidiotus perniciosus, that is highly destructive to fruit trees and shrubs throughout the U.S. Cf. armored scale.[1885-90, Amer.; named after SAN JOSE, California, where first found]
* * *Species (Aspidiotus perniciosus) of scale insect first discovered in North America at San Jose, Cal., in 1880 but probably a native of China. A waxy gray secretion (the scale) covers the yellow females, which are about 0.06 in. (1.5 mm) in diameter. The scale is elevated in the center and is surrounded by a yellow ring. The female produces several generations of living young each year. San Jose scales can completely cover tree branches and may eventually kill the tree.
* * *▪ insecta species of insect in the armoured scale family, Diaspididae (order Homoptera), that was first discovered in North America in San Jose, Calif., in 1880 but probably is native to China. The yellow-coloured females are covered with a gray circular scale about 1.5 mm (0.06 inch) in diameter, elevated in the centre and surrounded by a yellow ring. This waxy scale cover is secreted by the female and serves as a protective shell. After mating, the female produces living young called crawlers. There may be two to six generations per year.Sometimes San Jose scales can be serious pests, becoming so numerous that they overlap and completely cover tree branches. At those densities over time they may kill a tree. Historically, a lime-sulfur spray was once used as a control measure, but today, oil sprays are far more effective.
* * *