Oils in the viscosity range of 30 to 405 sec (SUS at 100°F) were evaluated for effectiveness by direct contact and residually against life history stages of the pear psylla, Psylla pyricola Förster. Adults and nymphs are killed by direct contact with oil emulsions well below the standard concentrations employed in practice. The residue causes a striking reduction in oviposition for an extended period after treatment. This effect ends as green tissue becomes exposed for feeding and oviposition. Mortality of adults caged on treated branches is higher than among adults on untreated branches. Newly hatched nymphs exposed to oil residue on bark may be killed. The egg is unaffected by direct treatment with concentrations of 20% oil or higher. Control under field conditions is likely due chiefly to kill of adults by direct treatment. Under field conditions an oil with a viscosity of 60 sec was as effective as those up to 405 sec. Possibilities for more effective use of highly refined, light oils are discussed.
Document Type: Research Article
Publication date: April 1, 1965
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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.