Ten years ago, Dan, a local beekeeper in his eighties, told me he never had used Apistan or any other miticide in his 40+ colonies. Instead he gave them each a grease patty with a little wintergreen oil mixed in. Grease patties were a popular treatment for a few years. They were made with a mix of Crisco and powdered sugar, squashed into pancakes and placed on the tops of the frames. In the process of eating or removing them, the bees got the oil on themselves and the mites didnâ€™t thrive. Beekeepers added terramycin to the patties to control foulbrood. Some, like Dan, added essential oils to control tracheal mites. People were surprised at how well colonies did.
Eventually, the grease patty fell out of useâ€”just another fad. I was suspicious that Danâ€™s mite control wasnâ€™t really controlling mites. I asked him if he lost colonies that he was treating. â€œOh I lost lots of colonies when I started, but now I hardly lose any,â€ he said.
Since then people have tried many different strategies for mite treatments, including small cell foundation, open bottom boards and Russian bees. In most cases their experience is similar to Danâ€™s. At first there is a high mortality. (â€œIt takes a couple generations for bees to get used to small cellsâ€, or â€œIt was a bad year weather-wiseâ€, or â€œRussians have to be managed differentlyâ€¦â€). Then, after a few years, the bees seem to survive pretty well without treatments.
In the last decade, bee scientists have tried these mite control methods with statistically insignificant results. In other words, they donâ€™t work, at least in the double blind experiments.
I suspected that something else was happeningâ€”that whatever treatment a beekeeper chooses, if it doesnâ€™t stress the bees too much, will seem to work.
My guess is that since the mites arrived in the Western Hemisphere, bees and mites have been adapting to each other. Dr. Roger Morse had observed in the late 1980â€™s that there was a high degree of variability in beeâ€™s resistance to mites.
When a hive succumbs to a mite infestation, two populations dieâ€”the mites and bees. The colonies that tend to survive are a combination of less virulent mites and more mite tolerant bees. When a beekeeper treats for mites, he props up a colony of both bad mites and weak bees, allowing them to pass their genes to the next generation.
Wild, unmanaged colonies are not extinct. Every year I get requests to remove bees from houses, barns, and trees. Most of the swarms I pick up come from wild colonies.
Ten years ago, I quit treating my bees with anything. I decided to keep more or less wild bees in moveable comb hives. One year after ceasing treatments, I had no bees. They all died of American foulbrood. I burned a lot of equipment. Later I caught a swarm in a bait hive and picked up a few others. Before, when I treated with terramycin and Apistan, Iâ€™d had one or two foulbrood cases a year. My last case of foulbrood was in 2003 or 04.
Ten years later, my equipment is full of bees. My theory is that the more empty equipment I have in the spring, the more bees Iâ€™ll have by fall. At least for the last three years my winter loss has been around 20%, better than the state and national average which has been 30% for the same period.
Dr. Larry Connor believes if local beekeepers organize, adopt a rigorous program of counting mites, selecting the most resistant colonies, flooding the area with selected drones, and conducting a complicated breeding program, it is possible to produce mite tolerant bees.
I believe itâ€™s already happening without any extra work. The wild colonies around here have done the hard work for me. They are flooding the DCAâ€™s with drones from mite tolerant colonies. Or the less nasty mites from the wild colonies are moving into my bee yard. Or both. Either way I donâ€™t have to waste time counting mites and reading warning labels on nasty miticide containers.
The Complete Idiot’s Guide to Beekeeping discusses beekeeping from a natural perspective.