Moore, W. 1933 Studies of the "resistant" California red scale Aonidiella aurantii Mask. in California.. Journal of Economic Entomology 26: 1140-1161.

Notes: This preliminary study considers the influence of a concentration of hydrocyanic acid on the mortality of A. aurantii, 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 may or may not be an important factor.