Bees pollinate all of our fruits, nuts, and vegetables. Honeybees contribute approximately $15 billion in pollination services to U.S. commercial agriculture annually. However, reliance on a single insect species, the honeybee, for the pollination of a huge portion of the human food supply can be dangerous. Indeed, this is especially true considering that honeybees are in decline from Colony Collapse Disorder (CCD), thus putting the global food supply at risk. The best alternative to honeybees is the native bees already present in the local environment. With nearly 3500 species in North America alone, the diversity of different forms, pollen-strategies, and behaviors of native bees provides a wide range of use for agricultural operations. It is estimated that native bees already annually contribute $3 billion to U.S. agriculture.
Each crop and each region in the world has its own characteristic group of native bee pollinators. There is very little data concerning regional make-ups of these native pollinator-guilds, which has led to our reliance on the European honeybees. During the past five years, we have surveyed the native bees in North Georgia. Our studies identify the mining bee, Andrena crataegi, and its close relatives, the Melandrena, as being the ideal native bee(s) for North Georgia Apple production. Other excellent apple pollinating native bees indentified were the Mason Bees (Osmia species), Carpenter Bees (Xylocopa virginica), and Bumble Bees (Bombus species). It is time to move to the next step: to develop habitat enrichments and other strategies to increase the abundance of targeted native bees in commercial apple orchards.
Ideal native bee habitat enrichments should: (1) be easy to construct, (2) be low cost, and (3) ideally have the potential to provide farmers with a supplemental income source. If farmers are able to harvest bee larvae (pupa cocoons), they can sell them to other orchard owners or to the public (e.g. to boost their backyard vegetable garden yields). In the current study, we will investigate a prototype habitat enrichment that meets all three criteria.
The project had 2 main objectives or goals.
The main goal of the study was to evaluate the potential of native bee habitat enrichment to boost native bee abundances of previously identified target bee species, as well as provide farmers with a supplemental income source.
The secondary goal was to continue surveying native bees for a sixth year within the apple orchards, with a focus specifically on the apple bloom periods. Significant weather changes, perhaps due to global warming, have resulted in drastically different growing seasons during the past 5 years. The apple bloom shifted 4-5 weeks earlier during the past 2-3 years, occurring in March. Last year the weather shifted back to the typical bloom in April. Native bees abundance and diversity significantly varied during these blooms. These much earlier apple blooms can impact which native bees are present to pollinated the flowers (e.g. mason bees, Osmia species, are more important during early apple blooms).