Evaluating the impact of local floral resource availability on fruit and vegetable pollinators and pollination

Wild bees provide valuable pollination services to crops around the world.  Many agricultural landscapes do not provide the resources necessary to support wild bee communities that are able to provide a sufficient level of pollination services to the crops.  In order to encourage wild bees, growers can adopt management practices that enhance the availability of floral resources on their farm.  It is unclear, however, how the local availability of floral resources influences pollinator behavior on crop plants and the resulting crop yields.  In this study, we investigated the relationship between local floral availability and the pollination of cucumber, muskmelon, and watermelon on small, organic farms in southern Wisconsin (USA).  We found that wild bee and honey bee visitation rate to cucumber, watermelon, and muskmelon did not respond to floral resources at a local scale.  Non-bee visitation to muskmelon increased significantly with increasing local availability of non-crop floral resources.  We also found no relationship between watermelon fruit set and the local abundance of non-crop flowers or insect visitation rate.  Future work will look at the relationship between insect visitation rate and floral cover and richness, compare the flower visitor community between crop and non-crop flowers, and assess how pollinator activity varies as a function of other farm factors (e.g., farm size, crop flower abundance, landscape context).