DeGrandi-Hoffman Gloria, Ahumada Fabiana, Zazueta Victor, Chambers Mona, Hidalgo Geoffrey, deJong Emily Watkins
Carl Hayden Bee Research Center, USDA-ARS, 2000 East Allen Road, Tucson, AZ, USA.
AgScience Consulting LLC, Tucson, AZ, USA.
Exp Appl Acarol. 2016 May;69(1):21-34. doi: 10.1007/s10493-016-0022-9. Epub 2016 Feb 24.
Varroa mites are a serious pest of honey bees and the leading cause of colony losses. Varroa have relatively low reproductive rates, so populations should not increase rapidly, but often they do. Other factors might contribute to the growth of varroa populations including mite migration into colonies on foragers from other hives. We measured the proportion of foragers carrying mites on their bodies while entering and leaving hives, and determined its relationship to the growth of varroa populations in those hives at two apiary sites. We also compared the estimates of mite population growth with predictions from a varroa population dynamics model that generates estimates of mite population growth based on mite reproduction. Samples of capped brood and adult bees indicated that the proportion of brood cells infested with mites and adult bees with phoretic mites was low through the summer but increased sharply in the fall especially at site 1. The frequency of capturing foragers with mites on their bodies while entering or leaving hives also increased in the fall. The growth of varroa populations at both sites was not significantly related to our colony estimates of successful mite reproduction, but instead to the total number of foragers with mites (entering and leaving the colony). There were more foragers with mites at site 1 than site 2, and mite populations at site 1 were larger especially in the fall. The model accurately estimated phoretic mite populations and infested brood cells until November when predictions were much lower than those measured in colonies. The rapid growth of mite populations particularly in the fall being a product of mite migration rather than mite reproduction only is discussed.
瓦螨是蜜蜂的一种严重害虫，也是蜂群损失的主要原因。瓦螨的繁殖率相对较低，因此其数量本不应迅速增加，但实际情况却往往如此。其他因素可能导致瓦螨数量增长，包括螨随采集蜂从其他蜂箱迁入蜂群。我们测量了采集蜂进出蜂箱时身上携带螨的比例，并确定了其与这两个养蜂场中那些蜂箱里瓦螨数量增长的关系。我们还将螨数量增长的估计值与一个瓦螨种群动态模型的预测值进行了比较，该模型根据螨的繁殖来生成螨数量增长的估计值。封盖子脾和成年蜜蜂的样本表明，整个夏季被螨侵染的子脾细胞以及带有寄生螨的成年蜜蜂的比例较低，但在秋季尤其是在1号场地急剧增加。秋季，在采集蜂进出蜂箱时捕获身上带有螨的采集蜂的频率也增加了。两个场地的瓦螨数量增长与我们对蜂群中螨成功繁殖的估计值没有显著关系，而是与身上带有螨的采集蜂总数（进出蜂群的）有关。1号场地身上带有螨的采集蜂比2号场地多，1号场地的螨数量尤其是在秋季更多。该模型准确估计了寄生螨数量和被侵染的子脾细胞数量，直到11月，此时预测值远低于蜂群中测量到的值。文中讨论了螨数量的快速增长，特别是在秋季，这是螨迁移而非仅螨繁殖的结果。
