Mason Bee House: PVC Pipe
I recently had the opportunity to tour the Plant Introduction Station at Iowa State University. They are conducting crop research using controlled pollination techniques. You can read more about the research that is being conducted at https://www.ars.usda.gov/research/project/?accnNo=424517.
I had worked with an awesome carpenter, Wes, last year to build a Mason Bee house out of oak and galvanized metal. We drilled what felt like a million holes to insert paper straws lined with parchment paper to assist with the reproduction cycle of the native Mason Bee. The goal was to collect the adult bee (housed in the paper tube) in the fall, overwinter them in my refrigerator to assist with a greater over-wintering rate for the bees. I don't think I got the house out soon enough last year, because I didn't have any adult bees in the house in the fall. They are an early spring bee - they do not survive or exist well in sweltering heat. I donated two of the bee houses we made to the Polk County Master Gardeners Demo Garden - I will need to see if I can find a picture.
Anyway, when I was at the Plant Introduction Station, during the tour we stopped at a station that was using native bees to pollinate certain plants. This team is using PVC pipe for the habitat, and placing straws inside the PVC pipe for the Mason Bee to lay her eggs. They attach the 'house' to rebar used in concrete construction. They just bend it at a 90 degree angle towards the top of the rebar, and hang the PVC pipe on the rebar, push the pole into the ground and turn the rebar facing Southeast so the bees catch the early morning sun. I didn't have my phone to take a picture, but found an applicable picture on the Internet. As you can see, they cut the pipe at an angle to afford a 'roof' over the straws, and attached this particular house to a cedar post. This is soooooo much easier than the house that I was building, so I wanted to share it - it might inspire others to offer this as an option for habitat for our native bees. I have shared information that I provided the Demo Garden below this picture. Get busy this winter when you have more free time than the spring, and create these very easy habitats!!!
Here is a website that offers the paper tubes for sale - to line the tubes, I just cut up parchment paper the same size as the tube, wrapped it around a dowel stick smaller than the diameter of the cardboard tube that I bought at Hobby Lobby, and slipped it in. It will allow you to pull out the adult bees for overwintering without destroying the paper straw, which can be a bit pricey - just remember, though, you saved money by using very cheap PVC pipe!.
Review my Make a Difference page to read a little more about native bees.
Mason Bee versus Honey Bee
Our native Mason bees have lived in America for millions of years. These native bees are called Masons because they work with mud to build and seal their nests. Honeybees were introduced by Europeans 400 years ago. Mason bees pollinate orchards and gardens, and are active in colder temperatures than honey bees. Though they won’t give you honey, they won’t sting you either – unless severely provoked.
Attracting the Mason Bee
In the wild, Masons build their mud sealed nests in natural tubes like reeds or holes in dead trees. If we provide 6” cardboard tubes 5/16” in diameter, we make their task much easier. The smooth tubes mean the female Mason bee has a lot less prep work to do on her nest – and she can channel that extra time and energy into laying more eggs.
The Mason Bee Life Cycle
The mud-sealed tubes contain the whole future population of Masons, males and females. All of last year’s adults have completed their lives by the end of the previous spring. Each 6” tube contains 6 or 7 separate compartments, each with one egg and a food pellet of pollen and nectar. In summer, the eggs hatch and the grubs feed. By September, they are transformed into adult bees that stay in the mud home until blossom time the following spring.
The female bee lays female eggs in the 4 or 5 most protected inner compartments - and just a couple of male eggs near the outside. The males chew their way out first in the spring and eagerly await the females. Mating is over quickly, and the females devote the rest of their short lives to finding a nest site, locating mud, making one cell at a time, provisioning it, laying one egg, sealing with mud – and on to the next one. The females go in frontwards with mud or food pellets – then backwards to lay the eggs.