The recent honey bee crisis and its implications for Michigan fruit growers

Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.

If you have been listening to radio or reading papers the last few weeks, chances are that you have already heard about the alarming honey bee die-offs around the country. The phenomenon is officially named “Colony Collapse Disorder” (CCD). This disorder has the media all excited because it is large in scale (25 states are affected), came in quick (colonies that were fine in August/September became collapsed around October/November), and hit people hard (many beekeepers with hundreds to thousands of colonies are losing 50-90% of their colonies). The worse of all of these? We do not know what causes it!

The symptom seems to be for bees simply to disappear, that is why initially peopled called it the disappearing disease (or fall dwindle disease). A colony with 40,000 bees in the fall, apparently healthy with lots of honey and pollen, suddenly has nothing or a handful of bees with a queen left. Very few dead bees are found inside the hive or near the entrance. Strangely, wax moths, small hive beetles are slow in moving in such newly abandoned colonies. Several possible causes come to mind. When tracheal mites (Acarapis woodi) first showed up in North American (circa 1983), we had bees disappearing also. The disappearing mostly happened during the over-wintering process – colony with small clusters or no bees in the spring because bees with their trachea plugged with mites could not make back to the colony after defecation flights or they simply fly out to die late fall.

A new species of nosema (Nosema ceranae, so named because it was discovered first in the Asian honey bees, Apis cerana) also showed up in the European bees (Apis mellifera, the only species we have in North America and Europe) in Europe during summer of 2006 and killed up to 60% of bees in some apiaries. Recently it is confirmed to be present here also in our bees in the United States. It could also be related to all the chemicals we have been throwing into bee colonies, which conceivably can weaken the immune system of honey bees and/or affect their learning and orientation. A few years ago, French beekeepers suspected that their “Mad Bee Disease,” where bees got confused and could not return home successfully, was related to the use of an insecticide called Gaucho. Unfortunately, most of these factors (tracheal mites and nosema disease) have been all ruled out as the cause of CCD. Scientists from Montana State University, Penn State University, North Carolina State University and USDA Beltsville Bee Lab have been collecting and analyzing a large number of bee samples. Hopefully we will have the answer soon.

Michigan will be impacted by this new disorder in several ways. First, Michigan is listed as one of the 25 states with CCD, which means some Michigan beekeepers are directed impacted by losing bees to CCD. A more widespread impact would be for beekeepers who do not experience this disorder but lose colonies anyway due to severe winter conditions. It is already common for beekeepers to lose 50-70% of their colonies during the wintering process because a combination of stresses: varroa mite, tracheal mite, nosema disease and residual pesticides inside colonies. Prior to the arrival of both mites, the normal winter loss is about 10-20% in the Michigan. This number has increased considerably the last few years. These beekeepers rely on buying package bees to replenish their lost colonies. There might be a significant increase of package bee price simply because of the bee shortage caused by the large CCD related die-offs. In 2006, the average price of 3 lb packages was already $65, compared to $45 five years ago. This price might increase again. A third way of impacting Michigan would be higher pollination fees for fruit and vegetable growers. In the past few years, apple, cherry and blueberry growers have been paying $35-50 a colony to pollinate their crops in Michigan. Again due to bee shortages, the fee per colony might be increased in Michigan. The extent of increase is not known.

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