A number of brands of tar washes and a home-made emulsion of American creosote oil were investigated as regards their constitution, effects on insects and toxicity to trees. The chemical constitution as regards distillation range, acid content, and types of washes are briefly discussed. At the proper dilutions these emulsions seem to be effective against rosy aphis, oystershell scale, San Jose scale, and pear psylla; also, they were reasonably efficient against the eye-spot bud moth. They did not seem to give any control against plum curculio, apple seed chalcid, apple leafroller, pomaria leafhopper of the apple, and had only a slight effect upon apple red bugs. While no permanent injury was observed to apple trees, mixtures containing more than 8 per cent of tar oils were generally quite destructive to swelling buds even tho they had not reached the silver-tip stage. Mixtures containing less than 8 per cent tar oils varied in destructiveness to buds according to dilution and variety of apple, but in no instance was the damage severe as regards the set of fruit. A 4 per cent mixture did not injure the swollen buds of pear or peach in limited tests. Mixtures of tar oils and lubricating oils proved very toxic to apple buds. The practicability of these washes for orchard use are discussed.
Document Type: Research Article
Publication date: June 1, 1932
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.