Effects of temperature adjustment with a heating device in weak honey bee colonies in cold seasons.

Temperature adjustment was used to buffer against changes in external environmental temperature by a heating device. Two groups of honey bee colonies Apis mellifera anatoliaca were used: one as experimental (20) and the other control (10), which were equalized in terms of the number of brood frames, frames with bees, food, hive materials, and health treatments. The experimental colonies were heated during the cold season, and the temperature and humidity inside the hive were recorded. The number of frames of brood, frames of bees, and Varroa destructor mite numbers were also determined for all hives. Results suggest that the number of brood frames and frames with bees increased significantly in the hives with the heating treatment. However, varroa mite numbers also increased significantly in the heated colonies in comparison to the control colonies. Colony losses were significantly less (15%) in heated colonies compared to a 40% loss in control colonies. This is the first account demonstrating that using simple heating devices can support weak colonies during the cold season in general, and colony losses can be reduced significantly from this heating treatment in cold seasons.