We’ll be lucky to get any Osmia lignaria bees this season as they generally try to already have a nesting site by now. They are a very early season pollinator!
However, there is a second native bee that may likely take up residence and provide effective pollination services all summer. Osmia californica, another mason bee, takes over about the time lignaria is done!
I might order some tubes of Osmia californica bees to kick start the local population.
If you have any interest in gardening or flowers, or follow any kind of agricultural related financial markets, you are likely aware that one of the ecological disasters we face is known as colony collapse disorder.
Basically, the worker bees in a honey bee colony die, get lost, or otherwise just cease to function. The cause has been attributed to pollution, mites, genetic degradation, pesticides, genetically modified crops, and/or a slew of other guesses.
It is a serious problem in that bee driven pollination of crops is what sustains much of the agricultural production in the United States.
Oddly, though, the european honey bee — the bee that everyone immediately thinks of as the One True Way that flowers are pollinated to yield seeds and crops — is actually an imported species and, frankly, a bit invasive at that.
Not only invasive, honey bees tend to be territorial in that they will actively defend their hive. As well, they really aren’t even that efficient as pollinators.
Not surprisingly, there are many native pollinators buzzing or flitting about. In the South Bay, the most noticeable are the carpenter bees as they are gigantic, relatively clumsy, totally non-agressive, fuzzy, and have a noticeably loud buzz while flying.
But they aren’t the true superstars of the native North American pollinators. For that, one should look to the Mason Bee or Orchard Bee (Osmia lignaria).
The mason bee is a rather docile flying insect that is considerably smaller than the carpenter bee. Like the carpenter bee, it is non-territorial, won’t sting unless seriously threatened, and is non-swarming.
The mason bee is an extremely efficient pollinator as a single bee may visit over a thousand blooms per day.
Clearly, this is a bug whose presence should be encouraged!
Fortunately, it is easy to provide housing for such a helpful critter. Roger is standing next to a mason bee home that we made over the weekend. We chose to make one out of a block of wood. However, bundles of reeds, bamboo or — even — appropriately sized straws work quite well, too.
To make a wood based bee house, start with a block of 4″x6″ wood. Soft wood — fir or pine — works best and it must be untreated.
As the nesting holes need to be at least 4″ deep, you’ll be drilling into the 4″ side of the wood.
Draw a grid on the wood with the holes all being separated by approximately 3/4″.
Don’t worry to much about making the lines straight. The bees really don’t seem to care!
At each intersection, drill a 5/16″ or 3/8″ hole that is at least 4″ deep, preferably about 5″ deep (no more than 1/2″ from all the way through).
Hole diameter and depth is rather critical. Any narrower or any shallower and your bees will tend to produce male offspring. The male mason bees don’t live as long and are not terribly good pollinators, by comparison.
A drill press — especially one with lasers — definitely makes this particular part of construction go much much faster!
Once drilled, I also sanded the front face of the house. Not so much because I was worried about the bees getting splinters, but because the wood was soft/wet enough that some of the holes had been a bit blocked by wood after drilling. Thus, sanding opened the holes a bit.
Fit a bit of scrap wood on top of a make shift roof. It doesn’t need to hang over that much. The roof exists mostly to provide a bit of early afternoon shade and to shield the front from water running down it during rain.
If you want, you can stain the outside, but not the nesting holes, obviously.
Mount your mason bee house with a South-SouthEast exposure. It should be at least 3 feet off the ground and should be exposed to the morning sun as the morning warmth encourages the nesting bees to get out and get busy.
Simple enough. I’m not sure we put our houses out early enough in the season. We’ll see. If not, there is always next year!