Winter mortality in the plum curculio, Conotrachelus nenuphar (Herbst), varied from 23 to 9%, based on studies extending over a 6-year period (winters 1954-55 through 1962-63). In 4 years there were no survivors of a southern strain exposed to winter conditions at Geneva, N. Y. Among beetles held in outdoor hibernation cages, only 4% entered the soil to hibernate; the others hibernated between leaf cover and the soil. There was slightly more winter mortality of males than of females. Females differed greatly in the exposure to low temperature required to terminate diapause. Males emerged from hibernation earlier than females and also appeared in host trees earlier. Over a 5-year period, from 33 to 62% of total emergence from hibernation occurred on a single day. Temperature docs not appear to be the sole factor accounting for mass emergence. Several weeks pass between emergence from hibernation and appearance in host trees. Early in the season, males predominate among beetles collected in host trees. As the season progresses, the females become predominant. About 40% or the beetles captured in the course of the season were males. The low percentage of beetles which can be collected on a single day under optimum conditions suggests that the beetles do not occupy host trees continuously.
Document Type: Research Article
Publication date: February 1, 1968
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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.