You are probably aware of the tracheal mite that has become established in North America and is decimating the continent's honey bee population. Despite quarantine, the mite has reached Vancouver Island and is now affecting local populations on Denman
Apiarists can control the infestation to some degree with the use of strips of miticide in each hive. But feral populations are approaching extinction. Unless there is a very dedicated beekeeper in the near vicinity, pollination by honey bees can no longer be a relied upon occurrence.
Fortunately there are alternatives; other native insects that can be encouraged and supported. One outstanding candidate in this area is the Mason Bee, Osmia Lignaria.
There are many descriptive about this insect on the web. Try a Google search using the operands mason bee.
I brought these bees to Denman Island in early March 1999, and mounted the nesting box in an appropriate site on my cabin wall (south side, under the eaves). I suspect a local population joined my "imports" in filling the new nesting site. By mid-summer there appeared to be a population of approximately 130 individuals undergoing pupation in preparation for next spring.
Subsequently I've attended several excellent seminars and workshops. Margriet Dogterom has received her doctorate from Simon Fraser University on her studies with Mason Bees. She is actively promoting them through her company Crop Pollination Consultants.
Unless the mites are controlled, the Mason Bee population will plummet after three years and stabilize at a lower sustainable level. To manage the mites, and maintain a large productive population, some work is involved. The bees will need to be extracted in their cocoon and cleansed of mites. The suggested process, to be undertaken in the October time frame, is to wash the cocoons in a very weak solution of bleach in water. Contact Margriet Dogterom at cpc@intergate.bc.ca , or attend one of her seminars, for details.
I could not figure how they were collecting so much pollen. There were not many blossoms nearby. Then I discovered how massive the supply of pollen was in a clump of large broad leafed maples in the corner of my property. Some of this pollen fell from the tree onto my metal roof and washed into the gutters forming a sticky yellow paste. I suspect those bees were continuously shuttling between the nest and the tree, diverting only for mud.
Some of the paper tubes I made were the length of computer paper. When I unrolled them in October I verified what I had been taught; anything over 6 inches is wasted. The bees closed up the tunnel end closer to the entrance and did not use the back end. Six inches appears to be optimal.
The bee population gradually diminished throughout the spring. The last of the survivors struggled through to the first of July, But they were in rugged shape, with tattered wings, and appeared to collapse from shear exhaustion.
I ALSO ENCOUNTERED SOME MINI-DISASTERS. When I undertook the onerous task of unrolling all those cardboard and paper tubes last October to wash the mites from the bees, I noticed that many of the tubes had a small hole in the side right alongside where each bee larva should be located. And inside, the bee was either missing or replaced by a rather ugly grub. Apparently the hole was a result of parasitic wasps. And I lost well over half of my population. The survivors were washed, dried, packed away in paper towling, and stored in my unheated garage.
Cardboard tubing is not a satisfactory material for mason bee nests
... To be continued shortly ...
| return to home page |