Thompson, W.L. 1939 Cultural practices and their influence upon citrus pests.. Journal of Economic Entomology 32(6): 782-789.

Notes: Heavy inert residue sprays of copper and zinc compunds not only inhibit the growth of entomogenous fungi which attack scale insects but create a condition favorable for purple and Florida red scale development, which appears to overshadow any appreciable effect the scale fungi might have. Purple scale (Lepidosaphes beckii), Pseudococcus citri, and Florida red scale are attacked by at least five species of entomophagous fungi.