The Importance of Native Bees

Above: Metallic bee species, Agapostemon sp., by Emily Luebke

by Rachel Floyd
January 26, 2021

Bees have been media darlings for years now making hobby beekeeping, “bee-friendly” flower gardens, and decorative bee houses trendy additions to thousands of backyard landscapes. It seems simple enough and we all like supporting a good cause, but the truth is, as ever, a bit more complex. The poster bee for all  “Save the Bees” campaigns that I have seen is the European honeybee. In response to this I would like to quote conservation biologist Sheila Colla who says, “Beekeeping is for people; it’s not a conservation practice. People mistakenly think keeping honey bees, or helping honey bees, is somehow helping the native bees, which are at risk of extinction.”1 By equating the broadly general word “bee” with the much more specific term “honeybee”, a successful awareness campaign with a whole lot of conservation potential has been rendered almost completely ineffectual. Even the cute bee houses mentioned above are not really what bees need. Native bees need just one thing and that is native habitat. This habitat will naturally include a perfect assemblage of plants that happens to need these bees as much as the bees need it and, as long as you aren’t over zealous in your yard work, there will be plenty of hollow stalks and bits of wood lying around to provide your local bees with plenty of prime real estate. 

Lasioglossum sp., by Devin Floyd.

Bees are on my mind right now, in the dead of winter, because I am planning to add on to my backyard kitchen garden this spring and I, quite selfishly, want to be sure that I have plenty of them around to take care of pollination. If your motives for supporting native bees are (like mine) less than completely altruistic then here is a quote from entomologist Bryan Danforth to consider, “An individual visit by a native bee [to a crop plant] is actually worth far more than an individual visit by a honeybee. Honeybees are more interested in the nectar. They don’t really want the pollen if they can avoid it. The wild, native bees are mostly pollen collectors. They are collecting the pollen to take back to their nests.”2  And from a University of California publication: “Research has shown that surrounding tomato fields with flowering plants improves yield. Tomatoes are both wind- and bee-pollinated, but bee-pollinated tomatoes have been found to have higher levels of vitamin C and to weigh more. Honey bees cannot pollinate tomatoes; they require a special type of pollination called ‘buzz pollination’ that honey bees cannot do. Buzz pollinators can vibrate their bodies to shake pollen from the enclosed anthers of tomatoes and other solanaceous crops. Bee pollinators of tomatoes include carpenter bees (Xylocopa spp.) and bumble bees (Bombus spp.).”3 I am also intrigued by a juicy tidbit, that I gleaned from a USDA pamphlet on native bees, which informed me that the southeastern blueberry bee (Habropoda laboriosa) forages primarily on blueberries4 (which are also native to North America). It is estimated that each female blueberry bee visits nearly 50,000 Vaccinium flowers in its lifetime, producing over 6,000 ripe blueberries.5 Native bees are certainly welcome in my garden, and I will let them know by including plenty of native habitat for them in my home landscape.

Bombus bimaculatus (Two-spotted Bumble Bee), by Devin Floyd

There are upwards of 4,000 native bee species in North America. They range from the truly tiny Perdita Minima, that measures in at less than 0.1 inch, to the familiar stout-bodied carpenter (Xylocopa) bees, that can be an inch or more in length.6 Most of our native bees do not live in large colonies like European or African honeybees do, preferring instead to excavate their own private chambers in the ground or in dead tree limbs, or to utilize the ready made tunnels that can be found in hollow plant stems or abandoned beetle burrows. In these quiet homes they lay their eggs and provision them with pollen to feed on when they hatch. Many baby bees overwinter in these well-stocked larders and emerge in spring to mate and begin the cycle anew. Bumblebees are a bit more social. They do live in small communities of up to 500 individuals. However, unlike the non-native honeybees, bumblebee colonies have an annual life cycle. At the end of the summer only newly emerged, fertilized queens will survive to hibernate through the winter. In the spring these young pregnant queens will emerge to look for a new (typically underground) nesting site.7

Andrena erigeniae, the spring beauty miner bee, by Emily Luebke

Honeybees will sip nectar from most any flower, but native bees tend to be specialists who have evolved exclusive, or at least preferential, relationships with particular native plant species. For example the spring beauty bee (Andrena erigeniae) will only dine on spring beauty (Claytonia virginica and Claytonia caroliniana) flowers.8 There is also a passionflower bee (Anthemurgus passiflorae) which rears its larvae exclusively on yellow passionflower (Passiflora lutea) pollen.9 For many native bees, the loss of just one plant species may mean ruin, and for many native plants the loss of a single species of bee could mean the same. This is the beauty of biodiversity. In a healthy system everything has its place and fills a particular need. How amazing to think that nothing there is wasted or unnecessary, and how different this is from the way that we humans currently live on the land! It is always instructive to look outside of ourselves at species and systems that have had so much longer to learn how to live well on this planet. Bees first appeared perhaps 130 million years ago.10 By contrast, it is thought that our earliest human ancestors evolved in Africa between 2 and 6 million years ago.11 We are still new here. Perhaps we will learn to live with more balance and grace if we are given enough time. 

Footnotes
1 https://www.scientificamerican.com/article/the-problem-with-honey-bees/
2 https://news.cornell.edu/stories/2011/10/native-bees-are-better-pollinators-honeybees
3 https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=25418
4 https://www.fs.fed.us/wildflowers/pollinators/documents/BeeBasics.pdf
5 https://bugguide.net/node/view/237062
6 http://assets.press.princeton.edu/chapters/i10593.pdf
7 https://xerces.org/bumblebees/about
8 https://springbeauties.wordpress.com/learn-the-pollinators/andrena-erigeniae/
9 https://www.indefenseofplants.com/blog/2019/8/6/a-tiny-passionflower-with-a-hardy-disposition
10 https://www.scientificamerican.com/article/the-beguiling-history-of-bees-excerpt/
11 https://humanorigins.si.edu/education/introduction-human-evolution