Under laboratory greenhouse conditions, moisture on Douglas-fir, Pseudotsuga Menziesii (Mirbel) Franco, foliage at the time of spray application enhanced toxicity of acephate, carbaryl, methomyl, sulprofos, and thiodicarb to western spruce budworm, Choristoneura occidentalis Freeman, approximately 2 to 14 times at LC50,. Toxicity of acephate increased the most (14.2 times). Possibly, moisture permitted a more even distribution of toxicant so that the probability of all larvae receiving a lethal concentration increased. When a precisely estimated LC90 (wet) of each of the five chemicals was applied to misted foliage and subjected to 0.76 cm of simulated rainfall at 0, 3, 7, or 14 d after spray application, time of rainfall application was not a significant factor in resultant mortality. Rainfall seemed to decrease mortality by the same average amount regardless of time of application. These results suggest that the application of sprays early in the morning when dew is present on foliage may be advantageous compared with applications to totally dry foliage.
Document Type: Research Article
Publication date: December 1, 1988
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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.