Bees are amazing creatures! Every day of their lives, bees are working for our wellbeing as they pollinate fruits, vegetables, nuts and wildflowers. Pollination of wildflowers is vitally important because these plants create the eco-structure of the food chain.
Honeybees, while non-native, enjoy a good deal of attention because of their commercial value in pollinating crops while producing honey, beeswax, pollen, propolis and royal jelly. Yes, it's amazing — all of that bounty is produced from a little insect.
Other busy bees and pollinators work their entire short lifespans of three to six weeks to help us survive while creating the next generation of their species.
(Left) An American bumblebee pries open a cream false indigo blossom. (Right) A common eastern bumblebee is covered in sunflower pollen.
Common eastern bumblebees are important pollinators frequently used in commercial greenhouses to buzz-pollinate tomatoes and sweet peppers. Bumblebees can vibrate and shake pollen loose for wildflowers such as cream false indigo, jewelweed and gentian. You can find cream false indigo and bumblebees along the edge of the Bennett-Johnson Prairie. Use the Arboretum’s Plant Finder to locate these and other favorite plants and trees. Minnesota is home to 24 species of bumblebees, and the University of Minnesota Bee Lab has detailed information about bumblebee lifecycles and conservation efforts.
More than 90% of all bee species are solitary bees; they lead solitary lives unlike social bees that live in a colony with their queen. Each solitary female constructs a nest, creates brood cells, lays eggs and forages for pollen to nurture her larvae by herself.
(Left) Leafcutter bees have jaws adapted for cutting leaves or petals. (Right) Evidence of leafcutter bees is being collected for research. Photo by Brit Forsbergs
Leafcutter bees create a succession of brood cells in small, hollow stems or tubes. They line the tubes and seal off each egg chamber with sections of leaves cut by using their adapted mandibles as scissors. Leafcutter bees cut circles and oval shapes. The oval leaf pieces line the tube or stem, and the round pieces section off each brood chamber. Each egg chamber also contains pollen that the bee gathered with the hair on its underside. Bees “belly flop” into pollen and do not have to pack it into pollen baskets. Leafcutter and other solitary bees are more efficient in gathering pollen with a 95% pollination rate, and do not have to share resources with other members of a colony. Some solitary bees can forage pollen from multiple sources while others rely on a specific flower. Studies show that one solitary mason bee delivers the precise pollination power of 60 to 100 honeybees.
You can also help with research about leafcutter bees on a MN iNaturalist site, Megachile Bee Leaf Cuts. Your photos of leaf cuts provide evidence of leaf species that leafcutter bees prefer for brood cells.
(Left) This type of longhorn bee gathers pollen from only sunflowers. (Right) A striped sweatbee surveys the world from a coneflower.
Longhorn bees and metallic sweat bees are solitary bees that nest underground. The summer sunflowers in the gardens around the Farm at the Arb are the perfect place to study many kinds of solitary bees. Because there are so many kinds of solitary bees, we have much to learn. Learn more about solitary bees on the Xerces Society website.
Hover flies are beautiful and efficient pollinators.
The “wanna bees” use mimicry to imitate bees! Hover flies or flower flies hang around bees and feed on nectar and pollen. They are the second most valuable pollinator after bees. Hover flies do “hover” like a bee, but they don’t sting, even though their coloring sends a more menacing message. Larvae of many hoverflies eat aphids and are used as a biocontrol. Eastern calligrapher is a type of hover fly named for the dramatic scroll markings on its abdomen. Many hover flies have delicate hyaline wings that are opalescent or glass-like.
Visit the Tashjian Bee and Pollinator Discovery Center at the Arboretum to learn about and observe honey bees and wild bees. Throughout the Arboretum, bumble, solitary and "wanna bees" are flying into their most active season, inviting you to take a closer look.
All photos by Zan Tomko except where noted.
Zan Tomko is an artist, horticulturist, Minnesota Master Naturalist Instructor and a co-founder of the iNaturalist Minnesota Lichen Map Project. To learn more about the University of Minnesota Extension’s Master Naturalist program, visit their website.