Bee Ready

In late March the native mason bees begin to emerge to begin their brief fruitful lives. They are one of nature’s best pollinators and will give you hours of enjoyment watching them come and go bringing food and mud to feed and protect their next generation. Harmless and amusing and easy to lure to your garden.

Yes, this is the winter issue and you probably think I am rushing things. Maybe a little—but here’s the deal. This issue of About Town runs through March. If I wait until the Spring 2012 issue to convince you to make or buy some Mason Bee houses, you will probably be too late to tempt 2012’s bees into new homes in your garden or orchard. Mason bees start and end their life cycle early and you don’t want to miss their stellar pollinating feats.

Because they are early bees they are perfect for fruit, nut, and berry pollination, as well as for early summer flowers. The bees are done for the year in early June having safely tucked away next year’s brood. Then, they die off.

The cycle starts with adult mason bees hatching toward the end of March. They developed from eggs inside the mud cells their mothers built in late spring and early summer of the prior year. Female mason bees prefer holes approximately 5/16″ diameter and 4″-6″ deep. Each hole accommodates four to six eggs and food, and she separates siblings with mud walls (nature is soooo smart). In her life she will produce about 34 eggs.

mason bee house

Half-occupied mason bee house. This was a test to see which material the bees favored for their homes. They preferred cardboard tubes to the white plastic, but eventually did use some of the plastic. You can buy the tubes online, or go to for inexpensive kits.

During late summer and fall of last year the eggs grew to maturity and have over wintered as adults. As soon as the class of 2012 breaks out of their adobe homes in late March and early April they begin breeding. The boys hatch first as mom laid all the boys to the front of the “house.” This ensures that if a bird or other predator attacks the nest, it only gets a few boys and leaves enough males and lots of females to make sure the line continues. The surviving males hang about the nesting site and literally jump the females as they hatch. My friends accused me of “bee voyeurism” as I find the whole life-cycle display fascinating.

As soon as a female has had a fling with often many suitors, she is off to begin finding a suitable home for her soon-to-bee brood. She also hunts for a good supply of just the right mud.

This will be my fourth year of beeing a bee landlord, and I will put new bee blocks right next to the ones from earlier years. Then the recently fertilized females will begin filling the holes in the new blocks. By the time the new blocks begin to fill up, all the class of 2012 will have hatched, bred and started nesting again. When they run out of new clean chambers, they will clean out leftover mud from old nests and begin filling them, too. (It is actually best to do this for them with a small brush, though, as it helps prevent a build up of fungus or other problems the bee might encounter in last year’s leftovers).

The nesting females are fascinating to watch as the fly back and forth, honing in on the particular hole they have claimed. She will be carrying pollen or mud, depending on a chamber’s content or stage. She uses the front of her head and her mandibles to place the mud, shape and smooth it. Her antenna are short and bent to accommodate this activity. Males have longer slightly curved antenna. Another difference between the sexes is size, with females often larger, sometimes the size of a honey bee. Mason bee size is determined by how well it was fed inside the nesting chamber. If it was a poor food year or unusually wet or cold, the bees will be smaller. Most mason bees in our area are black, and many people think they look like house flies. However, bees have four wings, flies just two. Bees have antennas, flies do not. Flies are pesky, bees are not.

From April through June I keep my bee blocks on a table under a porch roof open to the south and east. I then sit with breakfast or lunch and watch them go through their life cycle just inches from my face. The are solitary-gregarious bees, meaning they do not have a colony or a food source to defend. The females alone prepare for continuation of the line, but they like to live around others of their kind, like swallows. Because they have nothing to defend, they don’t attack the “big face” watching their comings and goings. They bump into me and go off, no problem. I have gently picked them up when they have been caught unaware by the cold and can’t fly, warming them in my hand. I have never been stung, I read that their sting is very mild, like a mosquito, and you have to actually maul them to get them to sting.

The bee blocks my friend Wilson Tinney has been making for the last two years have approximately 48 nesting holes, each can accommodate four to six bees. According to one source of information on bee pollination, just two of these mason bees could pollinate an apple tree as well, or better than, a few hundred honey bees. Given the bad news on honey bees for the past few years, mason bees seem like a good insurance policy.

bee blocks

A few of the bee blocks on my porch. If you make your own blocks, be sure to drill clean 5/16″ diameter holes. Wood debris in a hole swells with moisture and blocks the bee’s exit in the spring.

Mason bees go a-pollinating in cooler temperatures and less favorable weather than do honey bees. Mason bees are actually better at pollinating the blossoms they visit because they are “sloppy” hairy critters with no pollen “baskets” to keep from spilling a little of the last flower’s pollen on the next one. Mason bees also cross pollinate better because they go from tree to tree, while it is a honey bee’s habit to fill her neat pollen pouches from a tight group of blossoms on a single tree. The book The Orchard Mason Bee, the Life History, Biology, Propagation, and Use of a North American Native Bee, by Brian L . Griffin, notes an entire acre of commercial apple trees could be pollinated with as few as 250 mason bees.

The neatnik honey bee is said to pollinate just five or ten percent of the flowers she visits, while a mason bee trades pollen in about 90% of her visits. And, the mason bee visits about twice as many flowers per day as a honey bee.

Also, because mason bees are solitary, they are less likely to suffer the problems of the honey bee colony: mites, fungus infections, and now colony collapse disorder, whatever that turns out to be. The only downside to mason bees is no honey.

Mason bees do have predators such as carpet beetles, a species of parasitic wasp, mites (but because they only infest a single nest they are not the blight they are in a honey bee colony), and humans.

Sometimes other creatures will want to nest in your bee blocks. The most numerous one is a kind of wasp that nests later than a mason bee and will fill up any empty chambers in your block— I have a way to prevent some of that which I will show you when you pick up your block(s). This wasp makes the front mud plug very smooth and it is easy to tell her work from a mason bee whose mud plug is rough. Fortunately, nature has made the little bees so prolific that enough survive the rigors of winter and their enemies and competitors to keep the species going strong.

Worldwide, there are 200 species of mason bee, with the US hosting 140. Japan has used them for many decades to pollinate apple trees. The mason bees we are likely to see are Osmia lignaria. The Blueberry Bee is another family member, Osmia ribifloris, and pollinates blueberries.

By now, I am sure you are primed to become a “bee keeper.” This is a truly a “build it and they will come” project. Or, if you prefer, buy it and they will still come. You can buy the houses from Klyne Esopus Museum (your donation of $10 per block is greatly appreciated) and pick them up at my house. Wilson Tinney and I do this as a fund raiser for the museum, he builds them, I market and sell them. You can have a block or two or three and a tax deduction.

Place your Mason bee apartment block in a sunny east facing location and wait. We have native mason bees looking for affordable homes. Without your generosity they will nest in any hole that may or may not be as safe as the ones you provide. By placing the bee blocks near the plants/trees you want pollinated, you have a better chance of lots of mason bees to do the job.

These make great gifts for the gardener in your life or the child who loves nature—or needs to learn about “the birds and the bees.”