Cressman, A.W., & Broadbent, B.M. 1953 Susceptibility of resistant and nonresistant strains of the California red scale to oil and to Parathion.. Journal of Economic Entomology 46(5): 907.

Notes: The results show that the scales that had become most resistant to hydrocyanic acid were not resistant to parathion and were slightly easier to kill with oil than the strains less resistant to fumigation.