RELATIONSHIP BETWEEN CONE CROP SIZE AND CONE DAMAGE BY INSECTS IN RED PINE SEED-PRODUCTION AREAS

Abstract

AbstractAnnual cone abundance and insect damage to cones are highly variable in red pine seed-production areas. Cone crop size fluctuates almost unpredictably from year to year, but the number of insect-attacked cones tends to increase annually unless limited by cone abundance. Sixty-six per cent of the variation in cone damage can be associated with variations in cone abundance. This information, coupled with the fact that red pine cone insects are almost entirely dependent on red pine cones for food, implies that crop size is highly important in regulating populations of cone insects. Insects will be most devastating in areas where crop size varies little from year to year.