Efficacy of honey bees and native bees as pollen vectors for watermelon (Citrullus lanatus) and some ecologic predictors of pollinator abundance

Abstract

This study compares pollen carrying and deposition capabilities of honey bees and native pollinators such as the squash bee (Peponapis pruinosa), the sweat bee (Halictidae sp.), and the bumble bee (Bombus sp.), using crimson sweet watermelon (Citrullus lanatus) as the target crop. This study also measured various ecological predictors of pollinator abundance, such as distance to bee nest site, distance to wooded margins, number of field sides facing wooded margins, distance to undisturbed land, and percent nesting ground exposed nearby. The best ecologic predictors of native bee presence were distance to nest site and percent of ground exposed in nest site. All taxa observed exhibited a capacity to fully pollinate watermelon plants. While Apis mellifera carry the most target pollen in their bodies, Bombus sp. deposit the most target pollen on the stigma in a single visit.