Studies on rates of development and reproduction of California red scale, Aonidiella aurantii (Mask.) (Homoptera : Diaspididae) on citrus

Abstract

Red scale were reared in the laboratory on disks cut from lemon leaves floated on distilled water in plastic vials. Scales could be reared to maturity on the disks and females would produce crawlers. Rates of development measured at four temperatures using the leaf disk method were similar to data reported by earlier authors. Unfertilized females were found to remain alive and could be fertilized up to 16 weeks after the second moult. On the average, the longevity of unfertilized females was shown to be 3.5 weeks longer than that of fertilized females. The fecundity of females collected from the field was measured at a series of constant temperatures. Estimates of the capacity for increase (rc) and the innate capacity for increase (rm were obtained at four temperatures. Both these statistics were shown to be greatly influenced by temperature; rc was found to be an underestimate of rm at higher temperatures.