Intranidal temperature and body size of Africanized honey bees under heatwaves (Hymenoptera: Apidae).

It is generally accepted that temperate subspecies of honey bees can maintain stable temperatures inside their nests; however, little information is available on the cooling ability of tropical honey bees and the effect of high environmental temperatures on individuals. In this study, we registered temperatures in the brood area of strong- and medium-populated colonies of Africanized honey bees during heatwaves (maximum environmental temperature 44 °C) between April and May in the tropical Yucatán Peninsula of México. To evaluate the effect on colonies, we compared the body size of workers produced under high temperatures in the field and siblings produced at stable 34–35 °C laboratory conditions. We found that in the field, temperatures of the brood nest in both types of colony can increase above 36 °C during the hottest part of the day, especially in less strong colonies. Workers produced in the field were significantly smaller, compared to those reared in the lab at stable temperatures. This is a first study reporting body size reduction in honey bees as a consequence of possible thermoregulation disruption during heatwaves. We discuss our results considering potential effects of heat stress to Africanized honey bee colonies and tropical beekeeping. [ABSTRACT FROM AUTHOR]