SUNFLOWER POLLINATION - ABUNDANCE, DIVERSITY, AND SEASONALITY OF BEES ON MALE-STERILE AND MALE-FERTILE CULTIVARS

In a study of the diversity and abundance of bees visiting sunflower seed-production plots (6 male-sterile, 1 male-fertile cultivars), > 20 spp. of bees frequent the plots. Significant differences were noted among cultivars in relative attractiveness to bees. For native, nonsocial bees, the pollen parent was significantly more attractive than the male-sterile lines. Only 2 of the 6 male-sterile lines were significantly more attractive to social species (honey bees and bumble bees). The effectiveness of native bees as sunflower pollinators is discussed.