Haas, A.R.C. 1934 Relation between the chemical composition of citrus scale insects and their resistance to hydrocyanic acid fumigation.. Journal of Agricultural Research 19(6): 477-492.

Notes: Species discussed include Aonidiella aurantii, A. citrina, Aspidiotus lataniae, Icerya purchasi, Lepidosaphes beckii, L. ulmi and Saissetia oleae.