Lagowska, B. 1995a Tarcznik niszczyciel, grozny szkodnik kwarantannowy. [San Jose scale - a dangerous quarantine pest.]. Ochrona Roslin 39: 2, 8.

Notes: Reference is made to the wide food-plant range of Quadraspidiotus perniciosus, the severe damage caused by it and the difficulty of seeing it initially and of distinguishing it from other species of the genus. These aspects are discussed. Although for climatic reasons this quarantine species is thought not to present a great threat to fruit-tree cultivation in Poland at the present time, its great plasticity or a warming climate could lead to its becoming an important pest.