Establishing Bumble Bees as a Supplementary System for Honey Bees in the Pollination of Watermelon, Citrullus lanatus (Thunb.)

Abstract

The effectiveness of bumble bees, Bombus impatiens, and honey bees, Apis mellifera, on the pollination of watermelon, Citrullus lanatus (Thunb.), was compared at the individual bee level. Correlations between the number of bee visits a flower received and the resultant seed set and fruit abortion rates were established. Using `Royal Jubilee' watermelon, B-impatiens-visited flowers resulted in higher seed sets than A. mellifera when compared at equal bee visit numbers. This difference between bee types was highly significant. With respect to fruit abortion rates, no statistical difference between bee types was detected. However, bee visit count was significant. Increasing the number of bee visits received by a flower resulted in a lower percentage of aborted fruit.