Woodpecker shave been recognized for many years as a major factor in the natural reduction of Engelmann spruce beetle populations. A means of assessing their value has been developed. Five classifications of woodpecker feeding based on wood pecker work on 225 trees were studied. An analysis of population measurements showed a correlation between beetle survival and the woodpecker classification and the intensity of infestation in each tree. A heavy woodpecker classification resulted in very little survival at all intensities of infestation. Survival increased both with an increase in intensity of infestation and a lower woodpecker classification. The average reduction in populations increased progressively from 45 to 98 per cent as the woodpecker classification, which was highly correlated with caged survival, progressed from light to heavy. After woodpecker feeding, numerical survival of beetles was greatest in the moderate classification. The effects of woodpeckers on populations of the Engelmann spruce beetle can be evaluated by classifying woodpecker work and measuring the intensity of beetle infestation in the tree.
Document Type: Research Article
Publication date: October 1, 1958
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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.