According to Bee Informed (a Minnesota-based partnership that collects data about bee colony management/losses), bee colonies in Northern states suffered an average loss of 48% during the 2014-2015 winter[i]. Minnesota bees fared even worse-- a 58.5% average overwintering loss from the 84,062 colonies reported being managed[ii].
Minnesota winters are characterized as having cold (below freezing) temperatures with an average total snowfall of 50.6 inches[iii]. Currently, almost all bees purchased by Northern beekeepers—typically from Southern migratory beekeepers-- have never experienced a northern winter. By definition, Southern bees exhibit genetic traits suitable for climates more temperate than that of the North. Moreover, the bees purchased from Southern migratory beekeepers have typically been exposed to the stressors of the commercial beekeeping pollination industry.
Bolton Bees breeds bees for the conditions of the North. We use the process of elimination to determine which Queens will produce progeny. We keep records about each of our 300+ hive's performance. Each level of elimination is designed for a specific trait to be evaluated: over-winter ability, high honey yield, low mite load, favorable temperament and hygienic characteristics. Only hives that pass each elimination are allowed to produce Queens, which we then “graft” into new hives—passing the improved genetics into the new colony. We then repeat the process—continually improving the genetics
We have been successful in breeding MN-Hardy bees with select characteristics. Through natural selection, we have reduced unfit genetics. We had gradual success and had to endure major losses. As a result, we have gone from a 55% to a 93% overwintering success rate. We also have had success in breeding for high honey yield, low mite load, favorable temperament and hygienic characteristics.
1. Summary Winter Loss in Northern and Southern States Excluding Multiregional Operations. (n.d.). Retrieved July 18, 2016, from https://beeinformed.org/wp-content/uploads/2015/09/NorthVsSouth-RF.pdf.
2. Bee Informed Partnership .[ii] Losses By State. (n.d.). Retrieved July 18, 2016, from https://beeinformed.org/wp-content/uploads/2015/09/LossesByState-RF.pdf. Management Survey 2015
3. Average Annual Snowfall in Minnesota. (n.d.). Retrieved July 24, 2016, from http://www.currentresults.com/Weather/Minnesota/annual-snowfall.php