Beran, F. 1943 Untersuchungen zur Bekämpfung der San-José Schildlaus (Aspidiotus perniciosus Comst.) mit Blausäure. [Experiments on the control of the San-José scale insect (Aspidiotus perniciosus Comst.) with hydrogen cyanide.]. Arbeiten über physiologische und angewandte Entomologie 10(1): 1-31.

Notes: This paper discusses the effectiveness of hydrogen on Aspidiotus perniciosus. The resistance of the San-José scale insect is very much dependent on the insects' state of development and not on temperature. Species of host plants are listed although effectiveness does not vary according to host. The scale insect can be killed more easily on sick plants.