Honey bees are the most widely identifiable bee, however they are only 1 species of over 4000 in North America. Minnesota alone has more than 400 native species of bees, most of which people won’t ever see in person. Honey bees are very important to our food production, but it turns out native bees are much better for pollinating many of our native plants. The trouble is, native bee populations are facing many of the same hurdles that honey bees are up against. Honey bees have the advantage, as they are intensely studied and their colonies are able to move across the country in mass. This mass movement allows for pollination of crops like almonds, apples, and blueberries. Today pollination service is more profitable then keeping honey bees for honey production. This is due to many factors, but today honey bee colonies are less in number then what is needed for optimal pollination of the millions of acres of almond trees. We need bees. As more research is being done we have learned that native bees which have co-evolved with plants for thousands of years are more effective at pollinating those plants they are associated with. Thanks to some of these discoveries, we now use other species of bees to pollinate certain crops. Bumble bees are brought in to pollinate thing like tomatoes grown in green houses, alfalfa leaf cutter bees are brought into alfalfa fields to pollinate alfalfa for seed production. Orchard bees are brought into apple orchards for apple pollination. Farmers are even changing their field practices to accommodate squash bees which live in the fields of squash species and are incredibly efficient at pollinating all the different species of squash grown.
Bumble bees are probably the next most recognized bees and for good reason. They are large, noisy, and they form social colonies like honey bees, though their nests are most often found in old mouse dens, tree cavities, or inside building walls. Bumble bees are nectar foragers like honey bees, and they do make honey, just not in the quantities that honeybees do. Instead bumble bees are the muscle in the bee world. Bumble bees pollination methods are much more effective on plants like tomatoes and blueberries, because these bees are able to vibrate at a high enough frequency to knock the sticky pollen off these particular plants. They vibrate at the same frequency as the note C and this behavior is termed sonication. Check out some great videos by Prof. Karl Foord that show this phenomenon. https://www.youtube.com/watch?v=AKmrTlloJ9o
Learning more about bee species, I have found many more species living on the farm. Leafcutter bees leave signs of their presence by “cutting” or chewing round holes in foliage early in the spring and summer. Mason bees are easy to find on some of the first flowers of spring with their tiny metallic bodies buzzing lightly about. Mining bees are tiny too, and often found nesting in bare soil areas. Understanding nesting and foraging behaviors of different kinds of bees can help to identify many species of native bees. I discovered pollinator and bee hotels a few years back, and started to look into them. I had first purchased a couple bee hotels, and after seeing how fast bees took up residence, I realized it wasn’t just bees that use them. We love our bee hotels, and now that we have several on the farm. We look forward to watching for the signs of bees using the shelters. They are easy to make yourself with a little knowledge. It is important to note that as we learn more on these stem nesting bees, there are some key details to pay attention to when purchasing or making your own. First the stems or tubes should be from 4 – 6 inches long to avoid skewing populations of some bees species which lay female eggs at the back of the nests. One end of the tube should be closed, or have some backing, and research is indicating that stem nesting bees prefer darker stems or tubes. Making your own takes a little observation or identification of plants. Many native plants do have hallow or pithy stems which is what the bees are looking for. Gathering your own stems provides many different sizes which can provide nest sites for many types of bees. Of course deadheading your perennial plants can provide nesting habitat for bees just as well. This winter I began to experiment with my own design of bee hotel, and I look forward to trying them out this growing season.
Picture 1: Two spotted bumble bee on chive flower
Picture 2: Mason Bee on Siberian squill
Picture 3: Leafcutter Bee holes on Cup plant