It is well-known that the winter in north- a ern climates, which begin at 40 degrees c north latitude in the northeastern part of North America, is the season when honey k bee colonies are severely challenged. At h the first available opportunity, beekeepers h have to check their hives in the new year v and they often anticipate finding that some p ten to thirty percent of their colonies have a failed to survive. Many have stated that if li these percentages are not reduced, continu- c ing colony losses of these magnitudes can- a not be sustained. It is without question that h the winter season is when beekeepers expe- F rience the greatest rate of colony mortality. The northeastern part of the United States is considered a humid continental climate(Koppen), characterized during the winter months by a fixed period of snow and low temperatures which often fall below thirty-two degrees Fahrenheit (Fig.l). In addition to adverse weather conditions, many colonies may enter the winter season with insufficient stores of honey and pollen, aging queens, and small populations which are unable to sustain viable clusters. Further, extended confinements of bee colonies during cold periods restrict cleansing flights. The presence of parasites, particularly the varroa mite (Varroa destructor, Anderson and Trueman 2000), viruses and other pathogens, along with the debilitating effects of pesticides and fungicides found in the combs, exacerbate the aforementioned adversities. ;
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机译：众所周知，北方气候的冬季始于北美东北部北纬40度，是蜜蜂蜂群受到严峻挑战的季节。在第一个可利用的机会下，养蜂人不得不在新的一年中检查蜂箱，他们通常会期望发现大约百分之十到百分之三十的殖民地无法生存。许多人指出，如果不降低这些百分比，就无法维持这些数量级的连续菌落损失。毫无疑问，在冬季，养蜂人经历的殖民地死亡率最高。美国的东北部被认为是潮湿的大陆性气候（科彭），在冬季，其特征是有一段固定的降雪期和低温，其温度通常低于华氏32度（图1）。除了不利的天气条件外，许多殖民地可能会进入冬季，蜂蜜和花粉的储存量不足，女王/王后老化，人口稀少，无法维持成群的种群。此外，在寒冷时期延长对蜂群的限制会限制清洗飞行。寄生虫的存在，尤其是螨螨（Varroa destructor，Anderson and Trueman 2000），病毒和其他病原体，以及在梳子中发现的杀虫剂和杀真菌剂的破坏作用，加剧了上述不利条件。 ;
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