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April 30, 2009
A Tale of Two Bees
Last week, I put up the "bee condo" that was shown in my previous post on this blog. I had seen several bees that I thought were Osmia, but they weren't the typical metallic-blue of my old-time favorite, Osmia lignaria (which was the first bee I studied -- 31 years ago!). I finally netted one and realized it was a bee that I had not seen before. After some online searching, I know now that we have a good population of Osmia cornifrons around my house. At first I thought I might have had another new state record, but the species was introduced to NW Michigan in 2005 to aid cherry pollination. Furthermore, the species was introduced to North America in 1977 by Suzanne Batra, an apidologist at the USDA in Maryland. Osmia cornifrons (known in the bee world as the “Horn-Faced Bee or HFB) is supposedly easily managed with tube nests and can be set out in orchards to provide better pollination of cherry and other early-flowering fruit trees. The species is native to Japan, and there it accounts for a major portion of the pollination of apple trees. As I read the older literature, I remember reading the Batra papers in the late 1970s, and at the time, the significance of introducing another species to the US was lost on me. But now, with so much attention on invasive species, and the mere fact that dozens of species from Asia have taken residence in the US, I have to ask the question. Was that a good idea to purposely release a foreign species into the US without a long-term study on the potential effect on native bees? I also read where it was stated that the overwintering bees do not tolerate cold all that well (below 10 deg. F). Well, between 1977 and 2009, Osmia cornifrons has obviously managed to spread as a "feral bee" aside from the planned orchard usage. I suspect that it's been in my yard for more than a few years, given the good population that I see. It do not know if it has impacted native species negatively. I see both Osmias nesting side-by-side, and observed one nest usurpation of lignaria by cornifrons.
There is an obvious benefit to using the HFB in orchards – they are better at pollinating early-flowering trees under cooler conditions, they do not suffer from the same disease and management problems associated with honeybees, and are easy to ship and introduce into small fruit orchards.
I also made an additional set of nests available after I found a bunch of small paper tubes at the Scrap Box in Ann Arbor on Saturday, April 25. Within a few hours of setting them on the back of the house, I saw Osmia bees beginning to nest in them.
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Useful References Batra, S.W. 1979. New Bee... for small-scale Farmers. Agriculture Research. 27:3-4. Basic Biology and Management of the Japanese Hornfaced Bee Here is a movie that I took a few days ago, of Osmia cornifrons: Posted by mfobrien at April 30, 2009 11:39 AM CommentsIt's amazing what you can do with materials from the Scrap Box in Ann Arbor. Posted by: andypiper@comcast.net at May 1, 2009 08:47 AM Login to leave a comment. Create a new account. |