Until recently, native and feral bee populations met all of a farmers’ pollination needs. Farms were smaller, and closer to natural areas where native bee populations could easily recolonize a farm should an insecticide application kill resident bees. But with the advent of the industrial farm, habitat for pollinators has been drastically reduced─today, many of our agricultural landscapes are vast and lack sufficient habitat to support native pollinators or wildlife of any kind.
Despite the reduction of their habitat, native bees still play an important role in crop pollination across North America. Their pollination services are estimated to be worth $3 billion annually.
Meet the native bees
Native bees come in a wide range of sizes and colors─tiny sweat bees can be less than a quarter inch in length, while bumble and carpenter bees may be larger than an inch long. Some may resemble honeybees quite a lot─with hairy stripes of yellow, or white and black. They may be dark brown, black─even metallic green and blue with stripes of red, white, orange, yellow, and mother-of-pearl.
Some may look a lot like flying ants or flies.
Most are solitary, with each female creating and provisioning her own individual nest without the help of her sister worker bees. The majority of these native species are docile and unlikely to ever sting you.
Approximately 70% of native bees are ground-nesters, with a solitary female excavating her own nest tunnel, and from the one tunnel she’ll dig a series of brood cells─placing a mixture of pollen and nectar in each cell before laying an egg in it.
Other native bees nest in the narrow tunnels created by beetle larvae in dead wood─or they may use the center of pithy twigs. In North America, only about 40 species are actually “social” insects─that is─they live together in communities, with different working castes and the ability to communicate amongst themselves. Bumblebees, for example, nest in small cavities like abandoned rodent burrows, or grassy tussocks, and depending on the species─colonies may have a couple hundred worker bees by the middle of summer.
Benefits of native bees
Native bees are much more efficient pollinators than honeybees. In fact─it only requires about 250 female blue orchard bees to effectively pollinate an acre of apples─a task that would call for 1-2 honeybee colonies, each containing tens of thousands of workers.
Another benefit of native bees is that they are active in colder and wetter weather conditions than honey bees, and have more diverse foraging habits than honeybees. Unlike the blue orchard bees that forage for both pollen and nectar, in many orchard crops nectar foraging honeybees never contact the flower’s anthers─thus not actually pollinating the flower. And the shape of alfalfa flowers actually discourages honeybees from pollinating them, yet the alkali bee can easily collect pollen and nectar from them.
Having a high population of native bees on and around the farm can be a good insurance policy, should honeybees be in short supply to provide pollination for your crop. What’s more–studies have indicated that rather than creating a situation of short food supply─when honeybees and native bees are both present in an area, there comes a sort of friendly competition, whereas one spurs the other on to increase their foraging─thus increasing pollination in the area.
Growing plants for native pollinators has other benefits too─many plants that are beneficial to bees are also beneficial to the soil, and can reduce soil erosion. Planting bee-friendly flowering plants results in increased crop production resulting from more efficient pollination, which can provide additional revenue to the farm.
Native bees benefit crops!
- More than 100 species of native bees have been observed visiting the Wisconsin cranberry bogs.
- In California, 60+ species of native bees have been seen visiting watermelon, sunflower, and tomato crops.
- Native bees have nearly tripled production of cherry tomatoes in California.
- In fields of sunflowers, native bees improved the pollination efficiency of honeybees, causing them to move between male and female flowers more often. Only fields abundant in both native bees and honeybees had 100% seed set.
- In the blueberry barrens of Maine and Massachusetts, more than 80 species of native bee have been recorded pollinating the crops there.
- 100 species and more were documented pollinating the apple orchards in New York and Pennsylvania.
Consider the benefits and act today!
Many of the management techniques that farmers can use to encourage native bee populations on and around their farm cost little to nothing. If you should decide that you want to invest in your native pollinators, there are programs available through the Natural Resource Conservation Service to assist farmers in implementing a pollinator program. Stay tuned for the next post in this series to learn more about those methods and how you can better support native bees and pollinators on your farm.