Seasonal dynamics of bees in colonies with low and high levels of mite infestation.

<p>(<b>A</b>) Estimated bee numbers recorded in each hive in October, when a sudden decrease of bee population was observed in highly infested colonies. (<b>B</b>) Bee mortality over time. The error bars indicate the standard deviation; mean values significantly different are denoted with asterisks (*<i>P</i>≤0.05; **<i>P</i>≤0.01). Bee population in highly infested colonies reached minimum levels in October, because of a marked increase of bee mortality.