Studies of the "Resistant" California Red Scale Aonidiella Aurantii Mask. in California

Abstract

A preliminary study of the "resistant" red scale (Aonidiella aurantii) of California has been made involving the influence on the kill of the type of hydrocyanic acid concentration, the stage of development of the insect, the temperature of the host, the temperature and relative humidity preceding, during and after the fumigation, and protective stupefaction. It was found that the type of concentration and the percentage of insects in the resistant stages did not determine the effectiveness of the fumigation. Temperature and relative humidity had a decided influence. Protective Stupefaction mayor may not be an important factor.