Pollination Effectiveness of Honey Bees (Hymenoptera: Apidae) in a Kiwifruit Orchard

Abstract

Honey bees, Apis mellifera L., are used to pollinate orchards of kiwi fruit, Actinidia deliciosa (Chpvalier), but there is little direct evidence to support this practice. We measured the pollination effectiveness of individual foragers and insect foraging activity in an orchard vith 1 staminate vine for 13 pistillate vines. Honey bees made 98% of the anthophilous fauna with average densities of 3.18 and 1.19 foragers per 100 staminate and pistillate flowers, respectively. In 68 matched pairs of adjacent flowers, fruit set was 5.9% for flowers exposed to airborne pollen only and 39.7% for flowers that also received 1 honeybee visit. Fruits from bee-visited flowers contained 610 ± 80 (±SE) seeds, whereas those from control flowers had 110 ± 50 seeds, demonstrating that honey bees are effective pollinators of kiwi fruit. The effectiveness of honeybee visits was greater on vines surrounding a staminate plant than on those farther away, and some foraging bees may have released viable pollen which was then carried airborne to adjoining flowers.