Bigger = Better: Big Bees Fly Better in Hotter Temps than Smaller Ones Do

Arizona State University researchers have found that larger tropical stingless bee species fly better in hot conditions than smaller bees do and that larger size may help certain bee species better tolerate high body temperatures. The findings run contrary to the well-established temperature-size “rule,” which suggests that ectotherms—insects that rely on the external environment to control their temperature—are larger in cold climates and smaller in hot ones. The research will be presented today at the American Physiological Society’s (APS) Comparative Physiology: Complexity and Integration conference in New Orleans.

Insects fall into three categories:

• ectotherms (reliant on environmental temperatures for their own body temperature),
• poikilotherms (reliant on environmental temperatures but can control their own temperature—or thermoregulate—by sun- and shade-seeking or other behaviors), or
• endotherms (which can physiologically warm themselves).

“Bees fall along this entire range,” explained lead author Meghan Duell, a graduate student at Arizona State University. “Most [insects] employ some means of behavioral thermoregulation. As body size increases, it’s more likely that insects will be able to behaviorally and physiologically thermoregulate, especially in flying insects. Bigger bees, like bumblebees or the larger species in the work I’m presenting, are partially endothermic. They can warm themselves by shivering their flight muscles to produce heat but do not constantly physiologically regulate body temperature.”

Read more at American Physiological Society

Image: USGS Bee Inventory and Monitoring Lab from Beltsville, Maryland, USA via Wikimedia Commons