Flying, nectar-loaded honey bees conserve water and improve heat tolerance by reducing wingbeat frequency and metabolic heat production

• 成果类型: Article
• 署名作者: Glass, Jordan R.; Burnett, Nicholas P.; Combes, Stacey A.; Weisman, Ethan; Helbling, Alina; Harrison, Jon F.
• 署名单位: Arizona State University; Arizona State University-Tempe; University of Wyoming; University of California System; University of California Davis
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9152
• DOI: 10.1073/pnas.2311025121
• 发表日期: 2024-01-23
• 关键词: body-temperature regulation; hovering insect flight; apis-mellifera; thoracic temperature; thermal-stability; muscle efficiency; force production; centris-pallida; mechanisms; aerodynamics

摘要

Heat waves are becoming increasingly common due to climate change, making it crucial to identify and understand the capacities for insect pollinators, such as honey bees, to avoid overheating. We examined the effects of hot, dry air temperatures on the physiological and behavioral mechanisms that honey bees use to fly when carrying nectar loads, to assess how foraging is limited by overheating or desiccation. We found that flight muscle temperatures increased linearly with load mass at air temperatures of 20 or 30 degrees C, but, remarkably, there was no change with increasing nectar loads at an air temperature of 40 degrees C. Flying, nectar-loaded bees were able to avoid overheating at 40 degrees C by reducing their flight metabolic rates and increasing evaporative cooling. At high body temperatures, bees apparently increase flight efficiency by lowering their wingbeat frequency and increasing stroke amplitude to compensate, reducing the need for evaporative cooling. However, even with reductions in metabolic heat production, desiccation likely limits foraging at temperatures well below bees' critical thermal maxima in hot, dry conditions.