Six myths about mason bees
Wherever you find beekeepers you are likely to discover plenty of misinformation, fodder for the old joke about ten beekeepers having a dozen answers. It doesn’t even matter what kind of bees they keep, which means mason bees are no exception.
Don’t get me wrong—I adore mason bees and I have kept them for ten years, problem free. They are fun to watch, easy to raise, and they are excellent spring pollinators. Nevertheless, they alone cannot save the world, in spite of what anyone tells you.
Which bees are masons?
Before I get to the myths, let’s clarify what bees we’re talking about. In its broadest sense, the phrase “mason bee” can refer to any bee that collects materials from the environment and uses those materials to build a nest for rearing its young. However, when melittologists (the people who study bees) use the term mason bee, they are usually referring to several genera in the family Megachilidae.
The Megachilidae family is a large group that includes leafcutting bees, resin bees, woolcarder bees, and of course mason bees. The family includes bees that collect all kinds of stuff, such as leaves, petals, pebbles, mud, fibers, plant resin, or sometimes things like builders’ caulk. Depending on the species, they can be pretty open to new ideas. These bees often have large jaws that they use to collect their treasures. In fact, Megachilidae means large jaw or large lip.
Myth one: all mason bees are native
When bee scientists refer to mason bees they are usually referring to bees in the genus Osmia, which in North American includes about 130 different species. When non-scientists talk about mason bees they are usually referring to Osmia lignaria, the blue orchard bee. But on the east coast, folks may be referring to Osmia taurus or Osmis cornifrons, both introduced species.
So there’s your first myth. Not all mason bees in North America are “native.” Osmia lignaria is native, and so are many others, but those other two popular species (also known as the taurus mason bee and the hornfaced bee) are most definitely not. Like the European honey bee, they were brought here for a specific purpose and have since spread across the landscape.
Myth two: mason bees don’t sting
The second myth has to do with stings. I hear it all the time, “Mason bees don’t sting.” That’s an interesting theory, probably started by someone who never got nailed by one. Mark my words, mason bee females have stingers and they know how to use them.
On the other hand, each time I’ve been stung by a mason bee it was my own fault. The first time it happened, one walked up my arm and got under my watch band. I didn’t know it, of course, and when I moved my arm, the band tightened and she let me know. The sensation was so light I wasn’t sure if it was a sting or not. I wasn’t sure until the spot raised up and turned red like a mosquito bite. It lasted about 15 minutes and then disappeared.
My other mason bee stings were similar and barely detectable, but I think it’s important to understand that they do sting. People who choose to get mason bees because they are allergic to honey bee stings should be wary. Would they react in the same way? I have no idea, but I would not assume mason bees are safe for a highly allergic person. Check with your doctor first.
Myth three: masons can replace honey bees
No chance. While mason bees are highly effective pollinators, the ones we normally raise are short-lived spring bees. They work great in orchards, but they disappear for the year before most crops begin to bloom. Although they make an excellent addition to honey bees, they will never be able to replace them.
The same problem applies to most bee species. Because honey bees live in a colony where the workers are constantly replaced, the colony stays active all year long. This means honey bees can pollinate whenever they have flowers and weather warm enough to fly. On the other hand, most native species are active only six to eight weeks per year, so flowers are dependent on many different bee species to do the work.
Myth four: you need to buy mason bees
If you are not a commercial operator, you do not need to buy mason bees. In fact, last year in a bumble bee identification class, a member of the Xerces Society was asked, “Where is the best place to buy mason bees?” The speaker was adamant and forceful in his reply, “Do not buy bees!”
The audience member persisted and asked more specifically, “What if I buy them from — (she mentioned a well-known supplier)?” His answer: “Do not buy bees!”
Then she asked about leafcutters, and he replied, “Do not buy bees!”
Why? Because most native bees live their lives in a very small area, one they are adapted to. Once you begin shipping them around, you also ship whatever diseases and parasites they might have. In addition, you are putting them into an environment they are not accustomed to and they may die.
When you look at honey bees and bumble bees, you can see the damage done by shipping. We have assured that honey bees all over the continent have shared their diseases and parasites. We have shipped infected bumbles bee around to the point where an entire group of species is in rapid decline and faces possible extinction.
Why do we want to repeat this folly with mason bees? Why can’t we learn from our mistakes? I have to side with the Xerces Society on this one. Distribution of native bees should be strongly discouraged along with sell-back programs. If they are not native to your own backyard, they are not really native.
If you want to raise mason bees, put up mason bee housing and be patient. You will get a few the first year, more the second year, and after a while you will have many. They will be locally adapted, strong, and free from imported ailments.
Myth five: you must clean and bleach cocoons
Cleaning and bleaching of mason bee cocoons is not something that happens in nature. It becomes necessary when you have large single-species populations living in close quarters. Many of the common diseases and parasites have always been there at background levels, but their numbers become amplified when the host population becomes congested. If you have thousands of mason bees, you must control diseases and parasites.
Several years ago, I wrote to native bee specialists at UC Davis and the American Museum of Natural History asking about cleaning and bleaching. Their answers were the same: if you are not running a big operation, cleaning and bleaching is not necessary. For the backyard mason bee keeper with a garden and a couple of pollinator condos, no interference is necessary. If you are not running a factory farm, levels of pollen mites and parasitic wasps normally will not exceed background levels.
Myth six: masons will save the planet
No one bee species will save the planet. Not masons, leafcutters, nor honey bees. Saving the planet is up to us, not the bees. The standard advice holds true for all species of bees: reduce the use of pesticides, plant a wide variety of flowers and flowering trees, leave undisturbed patches of ground for soil-nesting bees, and provide habitat strips and water. To those I will add another: leave the bees where they are. Let them come to you. We can’t buy and sell nature because buying, selling, and redistributing is not natural at all.
Honey Bee Suite