Bachmann, F. 1974 Theoretical and practical aspects of the control of armoured scales (Diaspididae).. Mededelingen Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen Universiteit Gent 39(2): 755-760.

Notes: Several findings of fundamental importance about the biology of armoured scales, and the mode of action of chemicals active against these insects, have remained largely unknown to American and English entomologists, because the papers reporting them have been published in French or German. The author reviews these findings and discusses their relevance to chemical control. Quadraspidiotus perniciosus is among the species discussed.