Foraging Range and Distribution of Honey Bees 1 Used for Carrot and Onion Pollination 2

Abstract

A magnetic recapture system was used to determine the foraging range and distribution of bees from 389 hives in 29 apiaries (area about 12 km in diameter) to adjacent fields of carrots and onions grown for seed production. Bees from hives around the field perimeters showed intensive, localized foraging activity near their hives (mean flight distance = 266 m). Species diversity requirements were indicated when subpopulations bypassed profitable foraging areas and foraged on different crops at greater distances. Significant bee populations were attracted from distant apiaries, e.g., 3700 m. The mean flight distance to carrots (1663 m) indicated a greater attraction than for onions to bees from distant apiaries (557 m). The frequencies of pollen foragers were 7 and 66% for onions and carrots, respectively. Nectar sugar concentration was similar (ca 37%) for carrots and onions. Strategies are discussed for enhancing the isolation of nearby fields when interfield pollination is undesirable. Concepts are discussed concerning (a) differential flight range for pollen vs. nectar collectors, and (b) determination of relative plant attraction to honey bees.