The biology of the western pine shoot borer, Eucosma sonomana Kearfott, was investigated on young lodgepole pine (Pinus contorta Doug!.) from 1987 through 1989 in central Oregon. In the stands studied, 65-80% of the terminals were infested. Attacks were common on trees as small as 0.5 m tall, and infestation levels were high through the seedling and sapling stages. About 50% of the infested terminals contained two or more larvae. Symptoms of attack on lodgepole pine (short needles, short terminal shoots, dead shoots, and exit holes) were similar to those on ponderosa pine (P. ponderosa Douglas ex Laws.), but they were more subtle. Our observations suggest that exclusion of shoot borers increased the average height growth in two young lodgepole pine stands by :::::24%per year. At intermediate elevations for lodgepole pine (1,340-1,370 m), moth flight and oviposition began in April with the accumulation of 55 degree-days (DD) above5.5°C and before terminal growth on lodgepole pine had begun. The first larvae appeared in May at 240 DD, when moth flight and 75% complete and terminal growth on lodgepole pine was 40% complete. Larvae began leaving terminals for winter hibernation in early July at 600 DD, when terminal growth was 99% complete; the last larvae left in mid-August at 940 DD.
Document Type: Research Article
Publication date: February 1, 1991
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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.