San Jose scale(redirected from Aspidiotus perniciosus)
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San Jose scale
San Jose Scale
(Quadraspidiotus perniciosas), an insect of the scale family of the order Homoptera; a quarantine pest.
The adult of the San Jose scale is covered with a bark-colored scutellum. In females the scutellum is round and about 2 mm in diameter; the body is round and lemon yellow in color and has no eyes, antennae, legs, or wings. In males the scutellum is about 1 mm long and 0.6 mm wide; the body is light orange and has one pair of wings, three pairs of legs, and developed eyes and antennae. The San Jose scale is found on all continents. It was first found in the USSR in 1932; its focuses occur in the southern European part of the country, the Caucasus, Middle Asia, and the Far East. It damages more than 200 species of fruit trees, ornamental varieties, and leafy trees. The larvae winter under the scutella on the bark of tree trunks and branches. They turn into females and males in the spring. The female produces 100-300 larvae, or wanderers, which emerge from under the scutellum and adhere to the rough surfaces of the bark, where they remain motionless. There are from one to four generations a year. In sucking the sap from bark, leaves, and fruits, the San Jose scale creates spots and cracks in the bark, kills the bark, and causes the leaves to fall. Severely damaged trees die. Control measures include the use of decontaminated planting stock, the removal of dead bark from trunks and branches, the removal of dry twigs, the thinning of crowns, the destruction of root shoots and severely infested trees, the use of entomophages (ichneumon flies), and the treatment of plants with insecticides.
REFERENCEPopova, A. I. Kaliforniiskaia shchitovka. Moscow-Leningrad, 1962.
T. I. BICHINA