Collins, P.B. 1950 Scale insects.. Discovery 11: 158-160.

Notes: Discussion of economic insects including Lecanium ulmi, L. hesperidum, Cryptococcus fagi, Physokermes sp., Aonidiella aurantii, Chionaspis citri, Lepidosaphes beckii, Aspidiotus ostraeformis, A. perniciosus, Pinnaspis aspidistrae, Tachardia lacca, Kermes ilicis, Ericerus pela, Coccus cacti, Dactylopius opuntiae and Icerya purchasi.