Smith, H.S., & Armitage, H.M. 1931 The biological control of mealybugs attacking citrus.. Bulletin (Agricultural Experiment Station, University of California) 509: 1-74.

Notes: Species reviewed include Phenacoccus gossypii, Pseudococcus citri, P. gahani, P. krauhniae, P. longispinus and P. maritimus. Other species mentioned are Phenacoccus colemani, Pseudococcus aurilanatus and P. sacchari. Insect enemies of mealybugs are reviewed. Other topics are the history of development of biological control, mass production of Cryptolaemus, methods of handling beetles, trunk banding as an aid to control, the relationship of ants to mealybug control, the effect of spraying and fumigation on biological control, buildings and equipment, and economics.