Are bamboo tubes causing mason bee Armageddon?

The scientist in me is wary of the words “always” and “never.” Although some things are for certain—like death and taxes—“always” and “never” hoist red flags in my mind, warning me that whatever is being said needs a closer look.

Sometimes concealed with a synonym, those words often accompany a flawed statement. Meat is never good. Salt is always bad. You should never feed your bees. You should always rotate your brood boxes. Really? Says who? Time to click on something else.

Bamboo tubes as killers

Recently, I’ve read a spate of articles about the danger of bamboo tubes for mason bees. The articles claim that bamboo tubes are always bad. They will kill your bees. The tubes never dry out. They always grow mold. Bamboos is a significant reason for pollinator decline. Bamboo is an insidious weapon cultivated by the Chinese for the destruction of America. Oh, for heaven’s sake!

Bamboo tubes are the current bad boy in the mason bee world, accounting for all possible problems. Mason bees wouldn’t die, not ever, if we just stopped using bamboo tubes. Ten years ago, the problem was drilled wooden blocks. Back then, they harbored disease, stressed bees, multiplied predators, grew mold, and probably caused bee dementia. They were the sign of an incompetent mason bee keeper, just as bamboo tubes are today.

Wooden blocks and all the rest

At the height of drilled-wooden-block paranoia, I happened to visit the Oregon State University Bee Lab and had a long conversation with a professor of entomology. He told me the very best thing for raising cavity-nesting bees was drilled wooden blocks. But he conditioned them on a few details: drill holes of various sizes in each block and replace the blocks every few years. Sound advice.

A few years later, cardboard tubes took a hit. They were the worst possible housing because parasitic wasps could bore right through the sides of the tube and lay eggs in the bee larvae. At that time, bamboo tubes were recommended because they were harder for the wasps to penetrate, so safer for the bees.

And now, wouldn’t you know it, bamboo tubes are the bad guy because they retain moisture and promote mold growth. Bamboo tubes are causing mason bee Armageddon, and if use them, you are an agent of pollinator decline. Shame on you!

Variations on a theme

The truth is not nearly so riveting. Yes, poorly managed bamboo housing is hard on bees. Poorly managed drilled blocks are hard on bees. Poorly managed cardboard tubes are hard on bees, as are poorly managed paper straws. Do you see a pattern developing here?

What is important is the management of the housing, not the housing itself. The same holds true of honey bees. You can argue about Langstroth vs Warré vs Kenyan top-bar till the cows come home, but it’s the management that counts. If you do nothing, you get nothing (except dead bees). Regardless of whether you keep honey bees or masons or leafcutters or bumbles, it’s your management skill that makes the difference.

Personally, I use many types of pollinator housing, including bamboo tubes. My bamboo-grown mason bees do exceptionally well, even though I live in one of the dampest environments in the country. Yes, even the Pacific Northwest coast, the mold and mildew capital of the New World, is compatible with well-managed bamboo tubes.

Managing with bamboo

How does that work? Well, it’s easy. At the beginning of the mason bee season—about late March—I place last year’s full tubes in an emergence box near new bamboo housing. Before long, the bees emerge, mate, and fill the new tubes. As soon as nesting stops, which is around the end of May, I place the newly-filled tubes in fine-mesh bags and store them in my lightly-heated garden shed. When I say “lightly heated,” I mean it’s heated in the winter just enough to keep it from freezing.

The heat is for the sake of other things I keep there, like flower bulbs, potatoes, and carrots. But it works perfectly for mason bee tubes because it keeps them reasonably dry without total desiccation. A cool garage or basement could work as well. The mesh bags keep predators away from the filled tubes. Although it really isn’t necessary in my shed, I figure it can’t hurt.

So that’s it. The bamboo tubes are outside for two months, and sheltered for ten. No mold. No death and destruction. The bees emerge fat and healthy the following year. My biggest problem is often an over-abundance of mason bees, which are sometimes annoying when they start to appropriate every nook and cranny for their personal use.

If you decide to provide tubes for summer masons and leafcutters, just use a different set of tubes and take them inside as soon as nesting diminishes. Be sure to label the stored tubes so you know when to expect emergence the following year.

Why discourage potential allies?

Fatalistic articles about the dangers of bamboo tubes are short-sighted, written by people who expect everyone to be as perfect as they are. They try to make you feel stupid and incompetent if you use the current “bad boy” technique in your garden. If I recall, one particular article implied you were better off doing nothing than succumbing to the lure of bamboo.

But I so disagree. The greatest threat to pollinator health is not bamboo: instead, it is apathy and lack of awareness, or perhaps fear of bees and insects in general. People who don’t know or don’t care about pollinators can often be seen killing every living thing that isn’t green and shaped like grass.

Bring on the bamboo

I’m actually grateful to the producers of inexpensive bamboo bee housing because I find it is often the first step a person takes toward learning about pollinators and other insects. Because it is small and inexpensive, someone who is only marginally interested may give it a try.

People like to dip a toe in the lake before they dive in. Likewise, many people want to test drive an inexpensive pollinator home before they splurge on fancy condos and a library of books.

Yes, they might err here and there and kill some bees along the way. But if the process piques their interest in bees, if they begin to care, and if they become inspired to learn more about their environment, pollinators of all sorts will benefit in the long run—even if a few died in the process.

We need these beginners, and so do the bees. If cheap bamboo pollinator housing can change a person from a lawn spraying, grass growing, weed killing lunatic into someone who cares for the environment and the things that live there, bring it on! The long-term benefit will certainly outweigh any short-term deficit in management technique.

We need to get off our high horses and spend more time nurturing bee lovers instead of bamboo haters. If we lead with positive attitudes, we will end up doing much more for the bees, and that is what counts.

Rusty
Honey Bee Suite

With good management, bamboo tubes work well for many types of bees.