Hibernating Codling Moth Larvae1

Abstract

The location and abundance of overwintering larvae are detd. largely by the abundance of suitable cover. Apparently the larvae find hibernating quarters purely by chance and have no instinct for special locations or types of cover. No larvae were recovered from either the soil or the debris beneath any of the trees examined. Approx. 28% of the total worm population was collected on trunk and main scaffold limb bands, 3% remained in the harvested fruit, 39% was destroyed by predators and other natural factors, 15% escaped destruction and emerged, 12% was unaccounted for and only 3% overwintered on the trees. > 60% of all surviving larvae were caught in trunk and scaffold limb bands. 31% of the overwintering larvae were recovered from twigs and limbs < 4 in. in circumference at point of larvae location. Only 5.7% were recovered from the trunks and 7.4% from main scaffold limbs. Almost half of the recovered larvae were concentrated in a few favorable locations. An overwintering population of 41 larvae per tree gave a 1st-brood infestation of 36.4% the following season.