Mercurial Ointment, an Effective Control of Hen Lice
Journal of Economic Entomology
February, '17] LAMSON: MERCURIAL OIN1'MENT FORHENLICE 71 a protection of 69.1 per cent., but all the oil mixtures averaged 85.9 per cent. 17. Though the trees were retouched, treatment was less effective the second year than the first, the average protection the second year being 7.7 per cent as against 82.1 per cent for the first. 18. Up to a certain age, it appeared that asphalt varies in efficiency inversely as the age of the tree. In other words, the older the trees the less efficient the
... ess efficient the treatment. As a result of our investigations at Berryville, we concluded that the most practical manner of handling the borer properly is by worming the tree at the right time every year. SUMMARY 1. That the protection offered by white lead is not commensurate with returns. 2. That pruning compound is worthless as a borer protector. 3. That paper wrappers and wooden veneers, from first observations, appear to be impracticable. 4. Thll.t the cost of screening is too great to warrant its use as a borer protector. 5. That the use of asphaltum is attended with injury and that its efficiency as a borer protection is not worthy of the risk to the trees. 6. That worming the trees during the months of August and in early September is the most practicable as well as the cheapest method for the eontrolling of the borer.