Konstantinova, G.M., & Mordkovich, Y.B. 1982 [The California scale.]. Zashchita rastenii. Moscow No. 7: 63.

Notes: The California scale [Quadraspidiotus perniciosus (Comst.)] is an important pest of orchard fruits in the USSR and is under quarantine regulations. The effect of infestation is to weaken the trees and hence reduce yield. A single female gives rise to 100-150 crawlers, which spread the infestation, and according to region there may be 1 generation a year (in the Far East), 2-3 (in the North Caucasus) and 3-4 in Central Asia. The scale remains viable from -45 deg C to +45 deg C, and spread is mainly by means of planting material. Measures to be taken where the scale is already established are reviewed, as are also measures to prevent its spread. Some insecticides are recommended, notably trichlorol-5 [O-ethyl O-methyl O-(2,4,5-trichlorophenyl) phosphorothioate] or trichlorol-5M at 250 g/10 litres water at bud-burst, and also biological control by means of Encarsia (Prospaltella), Aphytis and Chilocorus spp.