LEAF DISC METHOD FOR REARING CALIFORNIA RED SCALE, AONIDIELLA AURANTII (MASKELL) (HOMOPTERA: DIASPIDIDAE)

A leaf disc method of rearing California red scale, designed primarily for experimental studies in the laboratory, is described. Discs (21 mm diameter) cut from lemon leaves were floated on distilled water in plastic vials. Crawlers of red scale, transferred by brush to these discs, developed and reproduced normally. A single disc could support up to 64 mature scales. Other scales, including Aonidiella citrina (Coquillet), Coccus hesperidum L. and Saissetia oleae (Bernard), were also reared using the same method. Discs cut from lemon survived longer than those cut from other citrus species, but discs from rough lemon and Valencia orange were also useful. The method was found to be particularly useful for laboratory experiments requiring rapid and accurate observations of large numbers of individual scales.