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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 11:39 AM | Comments (1) April 21, 2009Bee Condos
This spring, I am working with the Exhibit Museum to construct and set out a series of cavity-nest sites for solitary bees and wasps. Some of them will be placed in what has been called the "Butterfly Garden" at the side of the Ruthven Museums building. I call it the bug garden, because most of the insects that have been attracted are wasps and bees. The Bee Condo as shown here is very simple to make yourself. There are three 2x6x18" boards with 1/4, 3/8, and 1/2" diameter x 4.5" deep holes spaced about 1.5" apart. You can space the smaller diameter holes closer together, mix up the sizes per board, or keep them all one size, depending on what species you may want to attract to nest in them. Dan Erickson came up with the curved top and a piece of aluminum flashing to act as the roof. The 2x6" boards are simply nailed or screwed together. You can put a screw eye on top to hang the nest box, or set it on a pole or simply rest it against a fence or side of a porch. Use some scrap wood. Don't paint or coat the wood with anything. You can expect to see some mason bees (Megachilidae, genus Osmia) nesting in May, followed by leaf-cutter bees (Megachilidae, genus Megachile) in June and throughout the summer. There will likely be nesting in the cavities by mason wasps (Family Eumenidae), grass-carrying wasps (Family Sphecidae, genus Isodontia), and spider wasps (Pompilidae). It's great to have a garden where these insects get nectar and pollen, but including a place for them to actually nest in will be a wonderful addition. I'll work with the Exhibit Museum to come up with some educational and informative signage about the Bee Condo. I look forward to seeing the units occupied as soon as they become available. There are a lot of resources on managing non-social bees (meaning everything else that's not a honeybee or bumblebee), as some of them are great for pollinating orchards and alfalfa fields. Since most mason bees are native, they can endure the weather and emerge in synchrony with flowering fruit trees.
Some Resources on the Web: Posted by mfobrien at 12:15 PM | Comments (0) April 03, 2009Pest WatchingMichigan has had its share of disasters, the most recent of which seem related to industry and business. However, a much bigger disaster that most people seem oblivious to has been the devastation of our ash trees by the Emerald Ash Borer (EAB), or Agrilus planipennis. When we were first alerted about the EAB infestation about 10 years ago, it was of course, alarming. Here was this small beetle, living in SE Michigan for 5-10 years before anyone with entomological knowledge was made aware of it. If it had been some exotic pathogen that lived among humans for that length of of time and then started causing massive deaths, imagine the uproar and finger-pointing that would have gone on. However, ash trees are not people, but the loss of a major forest component will have ecological, industrial, and financial implications for many years to come. It’s hard playing catch-up when you are behind, and when a pest has a big lead, some things in hindsight, could have been done better. When the word “eradication” appeared in publications about EAB, I knew that there was no way that would happen. Unless there was a stiff penalty and a concerted effort to check vehicles for moving firewood and nursery stock out of infested areas, the EAB was going to spread. Some idiot moving firewood into a state park such as at Burt Lake ends up bringing in EAB and now ALL the ashes there are dead or dying. A lack of manpower and authority has been a big enabler to the EAB probelm. Someone bringing in infested wood should have a hefty fine leveled right there, with community service for additional punishment. Of course, a lot of this can be attributed to the constant under-funding of agencies that are responsible for keeping us alerted to new pests and the inspection of incoming shipments from around the world -- especially China. The US Forest Service, and APHIS PPQ have been under considerable pressure to do a better job -- which of course, can be accomplished mainly by hiring more inspectors and more money to find solutions to current and potential pest problems. You are probably wondering where I am going with all this. Last night, I attended the first meeting of the Michigan Cooperative Pest Cadre in Brighton, which is sponsored by the USDA. The purpose of the MCPC is to engage volunteers in surveying for potential pests that are not yet in Michigan, or have only recently been detected, or in the case of the Giant Hogweed, have been detected for some time, but eradication efforts to prevent the spread require detection of any previously unknown populations. Using citizens to help monitor pest species is an excellent idea. Look at how birders can converge at a single location when some rare bird is reported. Imagine using the power of the internet and the desire of many people to want to do useful things. Anyone with an interest in natural history can be trained in a few minutes to do what it takes to survey for some of the pest species. I think this is a great idea by the USDA and I hope it spreads and allows us to quickly detect some of these unwanted species. For some pest information on the four species being targeted thus far: I'll update later this year as I proceed to volunteer as a pest watcher. Posted by mfobrien at 09:59 AM | Comments (0) |
