Mason Bees

In the last 50+ years of keeping bees, I was always lead to believe that honey bees were the best pollinators around, my experiences this year, 2008, has shown me how wrong that statement is. Now before I get irate e-mails and phone calls defending honey bees I should explain what made me come to this conclusion.

I am a keen gardener growing lots of soft fruit and recently I added a small orchard to my holding. Apples, pears, plums, raspberries, gooseberries, blueberries, strawberries and blackcurrants, with melons and pole beans all needing bees. So you can see I have an extensive interest in pollinating all of the above, otherwise, my work in the garden would be a big waste of time.

Planning ahead I decided to add a hive of honeybees to the garden, in spite of the objections of neighbours. After all, all my crops need bees, don’t they? But in spite of that, the pollination wasn’t successful.

So what happened?
Where did those superb pollinators go to? They were flying almost every day, it’s not as if the weather went too cold or rainy, in
fact, it was what I like to call ‘Good Flying’ weather. So I took the time to watch carefully what was happening, bearing in mind the hive was positioned facing the trees, a clear flight path without extra obstructions. The bees would issue from the hive, a quick swipe of their antennas by their front legs and away they went straight over and past my fruit trees into the neighbours garden, into the decorative cherry trees. I had forgotten that bees become fixated when a nectar source opens the bees concentrate on that source, becoming fixed on that and little else. Here was the problem, the cherry tree blossoms open a few days before my fruit, by the time the cherries had finished the fruit blossoms were half over, and old blossoms do not pollinate well if at all.

You can imagine how frustrated I was to see the bees flying over the tops of my fruit trees, heading for a neighbour’s decorative cherry trees. My fruit was totally ignored, walking the trees day after day to find the blossoms being totally ignored is a most frustrating experience. I did have some pollination, mainly a few small solitary bees, a good number of bumble bees and a few wasps, but the honey bees were notable by their absence.

Later in the season, it became obvious, very little fruit, some of which was misshapen, a very poor overall set. This then caused me to spend time on the problem on what to do to improve the set of my blossoms. No point in caring for trees that failed to produce fruit, and without cutting down all the cherry trees in the subdivision where I live, which I’m sure my neighbours would not be happy about, I couldn’t at first see an answer.

I needed a bee that flew in dull weather,
which honey bees don’t, which didn’t require a great deal of my time, which could work quickly and not get fixated on one nectar source, preferably work without producing more honey. I talked around the problem, a search on the internet came up with Mason bees, in particular, Blue Orchard Bees or BOBs. Here was what I needed, adding to the points of interest to me, a bee which only flies approximately 300 yards from its nest site.

Lots of research later it was decided, Blue Orchard bees for me! I had put out nest sites years ago in the hope of encouraging solitary bees, but I really didn’t get any takers, the nest holes remained empty, so I have to start importing and hopefully starting a local population.

With the advent of CCD and the overall decline of European Honeybees, reverting back to a native bee, in that it is native and natural to North America, sounds like a good idea.

Mason Bees
are solitary and there are numerous strains, of which Blue Orchard bees are just one, they do not need a nest site with thousands of worker support. While they do prefer others of the same strain around, mainly for mating purposes, the females do most of the work in provisioning the nest tube. The males are good pollinators in their own right, but the forage is for their own use, and not for their offspring.

BOBs nest in tubes, under natural conditions, mainly those left by burrowing insects. With the removal of mature trees there has been serious habitat loss, so BOBs are in short supply and nest sites should be encouraged. These nest sites can be simple blocks of wood up to 6 inches deep, holes drilled approximately 5/16ths inch in diameter. The females will first close off the back of the nest tube with mud, hence the name Mason bees, on the bottom plug she will use pollen as the feed plus a small amount of nectar, and lay an egg. This section is then sealed with a mud plug, then immediately she will start on a second nursery cell and so on till she gets towards the front of the tube at which time she will lay unfertilized eggs, creating drones. Under good conditions BOB females will lay at least 3 females and 2 males per tube, after which she will seal the end and move to a second nesting tube.

Unlike honey bees, BOBs carry the pollen in a scopa beneath the abdomen, when a female lands on a flower she does what can be described as a belly flop, right in the middle of the blossom stamens. Whereas a honey bee lands on the side and walks down looking for the nectar site, possibly brushing past the stamen in passing. with each blossom needing up to eight visits by bees to effectively pollinate them, I would suggest the BOBs will do a better job, purely because of their approach to each blossom. By observation it should be obvious that BOBs main interest is pollen whereas honey bees interest is nectar for honey making. So with honey bees pollen transfer is accidental, but with BOBs transfer is deliberate, as the honey bee carries the pollen in baskets on the back legs, brushed there when the bee cleans itself, so transfer is accidental.

The BOB
is an incredible worker, visiting hundreds of flowers to charge each egg site and the increase in fruit crops using them is well documented, in some cases up to a 4 fold increase. Unlike honey bees they will start earlier in the morning, finish flying later in the day and dull weather doesn’t prevent them working.

I find it quite incredible that as far as the BOBs are concerned it’s all over in a few short weeks, the nest tubes are sealed and the larvae then eat through their stores, pupate then wait in the tubes till next spring before emerging. Even then it’s organized, the outer eggs turn into males which emerge a few days before the females, then hang around waiting to mate with the emerging females.

Caring for BOBs cannot in any way be considered labour intensive. They work without supervision, sealing off their young from predation with mud plugs. Some provision should be made to stop wood peckers accessing the nest site and then late in the fall the nest site should be taken in, opened and the cocoons cleaned to prevent infestation by pollen mites. This is a learning experience and ideally a search on the internet for Mason bees or Blue Orchard bees will supply sites where more information is available and where bees can be purchased.

I am in the process of purchasing bees for my own use for 2009, I have a nest site set and ready to accommodate them and as the saying goes, ‘God willing and the creek doesn’t rise’ I will be successful with lots of fruit next year.

If you have an interest in BOBs, then come back in the spring, I’ll update this page as I work setting up my BOB population, hopefully I will encourage others to help another endangered species and improve the overall fruit yield.
Update 2009