Science updates: Changes in cold tolerance & the overwintering of Italian honey bees

 

Science updates:

Changes in cold tolerance & the overwintering of Italian honey bees

 

The study investigates the changes in cold tolerance of Apis mellifera ligustica honey bees during the overwintering period. The research aims to understand the physiological responses of honey bees to cold temperatures and the role of various metabolites in their cold hardiness.

 

The study was carried out from late October 2016 to March 2017 in Taian, China. The researchers measured the super-cooling points (SCPs) of the bees, which ranged from -7.41 to -6.49°C, and found them to be lower than the average daily lowest temperature in January (-4°C). The protein content in the bees increased initially and then decreased during winter, while glycogen levels, a major energy source, dropped sharply in the middle of overwintering. The researchers also identified glycerol and low-molecular weight sugars and polyols (mannitol, sorbitol, and trehalose) as primary cryoprotectants, with their contents significantly accumulating during the winter.

 

For the first time, the study examined the expression patterns of antifreeze protein (AFP), protein lethal (2) essential for life-like (l(2)efl), and vitellogenin protein (Vg) mRNA during overwintering. The findings suggest that the seasonal super-cooling capacity is assisted by the accumulation of a complex mixture of winter-specific metabolites.

 

The research provides insights into the integrated feeding and management of honey bees to increase their winter survival rates. It also highlights the importance of understanding the cold hardiness mechanism of A. mellifera ligustica, which is crucial for beekeeping in China and other regions with cold winters. The study's results may contribute to the development of strategies to protect honey bee colonies during the winter months, thereby ensuring their survival and productivity in the following year.

 

Reference:

Qin, M., Wang, H., Liu, Z., Wang, Y., Zhang, W., & Xu*, B. (2019). Changes in cold tolerance during the overwintering period in Apis mellifera ligustica. Journal of Apicultural Research, 58(5), 702-709.

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