Published online by Cambridge University Press: 31 May 2012
One ounce of ten per cent granular disulfoton, per tree, applied to 3- and 4-year old blue birch in mid-May, was found to take approximately 2 weeks before reaching significantly toxic levels in the leaves. Thereafter, these levels gave excellent control of Fenusa pusilla (Lepeletier) for the 1-year-and-4-month period of the experiment (May 1964 – September 1965). At this dosage, it would appear, the chemical can indefinitely suppress populations of the birch leaf miner if applied once every 2 years.