Abbott, W.S. 1926 Determining the effectiveness of dormant treatments against the San José scale.. Journal of Economic Entomology 19: 858-860.

Notes: A count of the first-generation young per inch of new wood furnishes a reliable index of the effectiveness of dormant treatments against Aspidiotus perniciosus. A comparison of these counts will show the relative efficiency of various treatments. A high negative correlation between this count and the per cent of hibernating scales found dead indicates the reliability of the latter count. The correlation coefficients shown indicate that in these experiments the records taken 30 days after treatment were accurate.