Pollinators (read: native bees) hold a place near and dear to my heart. I’ve also had the great fortune of being able to study them in the wild, learning about their wondrous ways and marveling at their impressive diversity. I’m excited that June is National Pollinator Month because it gives me an excuse to write about everything bees! Let’s kick it off with a listicle to whet your appetite for more bee reads to come. But before I start, here’s the introductory paragraph to the US Forest Service’s handy guide to native bees that nicely sums up the theme for this month’s blog posts:
“Native bees are a hidden treasure. From alpine meadows in the national forests of the Rocky Mountains to the Sonoran Desert in the Coronado National Forest in Arizona and from the boreal forests of the Tongass National Forest in Alaska to the Ocala National Forest in Florida, bees can be found anywhere in North America, where flowers bloom. From forests to farms, from cities to wildlands, there are 4,000 native bee species in the United States, from the tiny Perdita minima to large carpenter bees. Most people do not realize that there were no honey bees in America before European settlers brought hives from Europe. These resourceful animals promptly managed to escape from domestication. As they had done for millennia in Europe and Asia, honey bees formed swarms and set up nests in hollow trees. Native pollinators, especially bees other than honey bees, have been pollinating the continent’s flowering plants since long before the arrival of honey bees. Even in today’s vastly altered landscapes, they continue to do the yeomen’s share of pollination, especially when it comes to native plants. The honey bee, remarkable as it is, does not know how to pollinate tomato or eggplant flowers. It does very poorly compared to native bees when pollinating many native plants, such as pumpkins, cherries, blueberries, and cranberries. Let us take a closer look at this forgotten treasure of native bees.”
Fun facts about native bees:
- There are 4000 species of native bees in America! Just to re-emphasize what the US Forest Service says above, because this is SO important, honey bees are non-native to the US, and before there were honey bees, crops, trees, and wildflowers were all pollinated by native bees. Native bees evolved to pollinate their local native plants, so it makes sense that they would be the best, most natural candidates for pollinating those same native plants now. Honey bees are definitely more effective at pollinating certain crops, but our collective dependence on honey bees for pollination has gotten us into trouble – honey bees aren’t doing so well, as you might have heard. Part of this is because domestication isn’t all that healthy for them, especially when used in large-scale farming operations. Honey bees also tend to outcompete native bees and therefore harm native communities, so sometimes they can do more bad than good. I’m simplifying all of this because this is a listicle, but the research is accurately reported in many sources – check them out with a google search on “native bees and honey bees” if you’re interested, just make sure the sources you read are citing scientific articles published in peer-reviewed journals.
- Some bees mimic wasps, and some flies mimic wasps and bees.
Both of these are flies! Left: a bee mimic, right: a wasp mimic. This is a super cool adaptation meant to deter predators. It also makes it difficult to differentiate between wasps, flies, and bees when they’re flying around outside. As a field tech, I eventually became adept at this skill and can pretty easily ID the insect family on the fly, but this was my full-time job and it took a lot of practice. If you’re interested in learning the specific characteristics that differ between these insects, here’s a good place to start: https://beespotter.org/topics/mimics/
- Native bees are often very small and go by unnoticed, but you can observe them almost anywhere if you are patient.
They can often be as small as an ant, so keep your eyes peeled or use a magnifying hand lens. If you sit in front of a clump of flowers in the summer between 10 am and 2 pm when it is sunny, there is no wind, and the temperature is above 70 degrees, you’ll probably see some native bees within 15 minutes. If you don’t, you’re likely choosing the wrong clump of flowers. Unless you strategically plant your garden, your best bet is to go searching in a natural prairie or forested area. Remember that these are native bees, and so may be less likely to visit the types of exotic flowers often sold by nurseries and landscapers.There are many different types of native bees, but here are some of the more common groups:
Agapostemon are my favorite kind of native bee, with some species sporting characteristic yellow and black stripes on the abdomen, and some completely metallic green or blue.
Augochlora are beautiful metallic green/blue bees that can look similar to Agapostemon.
Colletes are more “classic” looking bees, with yellow and black stripes and plenty of fuzz.
Hylaeus are quite small, with a mostly black body often featuring yellow markings around the face, legs, and upper thorax. For scale, the tiny black speck on the flower petal in the left-hand image is a Hylaeus bee!
Andrena are another group of mostly black and hairy bees:
By now, some of the species are starting to look pretty similar. If you’re interested in actually learning specimen ID, there’s a wonderful, specific guide that takes you through identifying characteristics one by one http://www.discoverlife.org/mp/20q. This is really fun, but requires a microscope; bees that have been caught, preserved, and properly curated; and plenty of pre-identified museum specimens with which to compare your specimen. But with a little training, motivation, and the internet at your disposal, anyone can do it! One caveat: I am sure most people could easily learn to identify bees to genus, but when it comes to species IDs, for some speciose, cryptic, or rare genuses like Lasioglossum and Hylaeus, you really need an expert taxonomist to verify the ID. I always encourage citizen science, so if you’re interested in this kind of thing, contact me and I can get you in touch with the right people!
A few more genuses include Nomada, Anthidium, Megachile, Bombus, and Osmia.
A quick caveat: not all bee species that you can observe in the wild from these groups are native, but the vast majority are. There are about 20 non-native bee species in America, including species of Megachile, Hylaeus, Chelostoma, Hoplitis, Anthidium, and Andrena. Learn a bit about these species here:
- Bees are descended from wasps, but while wasps are carnivores and sometimes even cannibals, bees are herbivores.Bees actually eat both nectar and pollen! Adults mostly eat nectar, but pollen is also stored as food for larvae. Perhaps intuitively, nectar supplies bees with high energy needs, and pollen provides more protein.
- Some bees are generalists, while others specialize on certain flower species.Bumblebees often pollinate all different flowers, while some groups of bees specialize on certain flower groups or species. Squash bees pollinate cucurbit plants like zucchini, pumpkin, or squash. Macropis bees only forage on loosestrife, and Anthemurgus passiflorae is a highly specialized bee that only visits flowers of the species yellow passionflower, Passiflora lutea. Some of this is based on the bee shape and size “matching” with flower shape and size- only long-tongued bees and tiny bees can access nectar at the bottoms of long, narrow flowers, while almost all bees can reap the nectar and pollen rewards of sunflowers and other asters.
- Different bee species display varying amounts of sociality.
Everyone knows the honey bee is super social and lives in colonies with rigid caste systems, cooperation, and even dances to communicate with each other. However, many of the native bees listed above live in varying states of solitude. Some live together at certain life stages, some create nests and leave the offspring to fend for themselves, and some, like bumblebees, still live in colonies but don’t reach the level of sociality that honey bees do.
- Miners, leaf-cutters, masons, carpenters: different bees have different nesting habitats.
Mining bees dig holes in the ground and live in them. Species from Andrena and Colletes are miner bees. Osmia are carpenter bees that carve out nests in dead wood, and Megachile are mason bees that nest in holes and leaf cutters that use pieces of leaves to line their nests.
- Some bees are nectar “robbers.”Remember what I said about longue-tongued bees tending to drink nectar from long-tubed flowers, and short-tongued bees foraging on smaller flowers? Well, it would be nice for science if nature complied with these seemingly obvious rules, but as is usually the case, nature is more complex than that! Some bees have learned to “cheat” the system by poking holes in the bottoms of nectar tubes and drinking nectar by using their tongue as a straw. From an evolutionary perspective, this behavior “cheats” the system: the bee gets all the benefit without helping the plant out by pollinating it. Usually, pollination is classified as a “mutualism,” where two partners get mutual benefit from interacting, but in this case, the plant misses out.
If you found this interesting, look out for future posts in which I’ll be writing about topics such as attracting native bees to your yard, native bees’ role in agricultural crop pollination, the science on the effects of pesticides on bees, and native bee conservation. The US Forest Service’s native bee guide also provides more detail on many of the topics discussed here. The Xerces Society also plays a prominent role in pollinator protection – for an excellent resource on all things pollinators, visit their website here.
Happy Pollinator Month! 🙂
To learn more about my research on bees, see this article in a New Jersey Watershed Association newsletter: https://www.raritanheadwaters.org/2015/10/29/the-buzz-on-bee-research-at-fairview-farm/
If you think insects are really cool and you want to learn more about how they live their lives, check out this fun piece about insect communication that you can find here: https://esuglia.wordpress.com/2015/10/02/insect-communication-its-an-art/
More bee & insect articles by yours truly!
Bee mimic: By USGS Bee Inventory and Monitoring Lab from Beltsville, USA – Asilidae, U, Side, Carroll Co., MD_2013-07-23-15.07.52 ZS PMax. Uploaded by Jacopo Werther, Public Domain, https://commons.wikimedia.org/w/index.php?curid=28757280
Wasp mimic: By Bruce Marlin [CC BY-SA 2.5 (http://creativecommons.org/licenses/by-sa/2.5)%5D, via Wikimedia Commons
Agapostemon bee: By Judy Gallagher [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons
Augochlora bee: By maxson.erin – cf Augochlora pura F, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=44336582
Colletes bee: By S. Rae from Scotland, UK – Colletes, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=50700247
Hylaeus bee images, in clockwise order from left to right:
By Orangeaurochs from Sandy, Bedfordshire, United Kingdom – Solitary bee (Hylaeus?), Sandy, Bedfordshire, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=48913744
By Orangeaurochs from Sandy, Bedfordshire, United Kingdom – Solitary bee (Hylaeus?), Sandy, Bedfordshire, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=48913743
By Katja Schulz from Washington, D. C., USA – Yellow-faced Bee, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=40573628
Andrena bees: By entomart, Attribution, https://commons.wikimedia.org/w/index.php?curid=867032
Osmia bee: By Judy Gallagher – http://www.flickr.com/photos/52450054@N04/9047304581/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=54772670
Bombus bee: By H.Kohori – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=26831732
Megachile bee: By maxson.erin – Megachile rotundata F, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=50989578
Anthidium bee: By Juan Emilio from Las Palmas de Gran Canaria, España – Anthidium palliventre??, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=24985755
Nomada bee: By Judy Gallagher – http://www.flickr.com/photos/52450054@N04/26307754972/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=54772930