Thompson, W.L. 1939a Factors influencing the development and control of scale insects on citrus.. Proceedings of the Florida State Horticultural Society 52nd (1939): 104-111.

Notes: Lepidosaphes beckii and Chrysomphalus aonidum are the two most important species of scale insects from an economic point of view. This paper discusses the effectiveness of control programs, timing of chemical applications, stage of growth the majority of scales are in at the time of application, degree of infestation, type of trees to be sprayed, method of application, kind of equipment and the concentration of the scalecide.