Thermodynamic assessment of the impact of the climate change on honeybees

Honeybees are among the most sensitive biological species to the changes in environmental conditions. Since pollination is necessary for the cultivation of more than 75 per cent of the crops used directly by the people worldwide, any injury to the honeybee population due to the climate change may jeopardize the food security. Therefore, thermodynamic parameters which are implemented on the honeybees under the prevailing environmental conditions and which may be implemented in the case of an anticipated temperature change are assessed. Work performance and entropy generation by the honeybees while resting, foraging for nutrients outside of the hive and fanning the hive are assessed based on sucrose metabolism. The minimum entropy generation accounted was 1.2 x10-7 W/g honeybee K while the 1-7 h old young honeybees were resting under atmospheric pressure with 0.5 M of sucrose supply at 15 μl/min flow rate in the hive. The maximum entropy generation, 7.2 x10-5 W/g honeybee K, was accounted during foraging at 35oC at shade with 0.5 M of unlimited sucrose supply. With 3,000 honeybees, work performance was 3.17 kJ/kg dry air, heat generation was 4.44 kJ/kg dry air and the entropy generation is 161.6 W/g honeybee K while raising the temperature of the hive by 1oC. On the other hand, they have to perform 4.5 kJ/kg dry air of work, generate 7.27 kJ/kg dry air of heat and 308.9 W/g honeybee K of entropy to reduce the temperature of the hive by 1oC. The results show that during cooling by 1oC the honey bees performed 1.4 folds of work and generated 1.9 folds of entropy when compared to that of heating by 1oC, implying that global warming may create 90 per cent more entropy stress on the honeybees, when compared to that of a potential global cooling.