Fig. 5.
Mean metabolic rate of resting honeybees in dependence on ambient temperature (Ta). Filled circles, winter bees; filled squares, summer bees. Vertical bars indicate SD. Range of validity of fitted Eq. (1) parts (A–C): 0–51.75 °C. Bold line: main range of honeybee activity. TL = upper lethal temperature (51.8 °C; Ken et al., 2005). Number of values (10 min intervals)/bees: 5.0 °C: 757/11, 7.3 °C: 398/12, 9.7 °C: 145/10, 14.1 °C: 166/5, 18.2 °C: 180/5, 22.4 °C: 101/5, 26.5 °C: 167/4, 30.4 °C: 127/4, 34.5 °C: 217/6, 38.1 °C: 177/6. Additional curves of forager bees from (Rothe and Nachtigall (1989), Warburg O2 manometry); (Lighton and Lovegrove (1990), flow through CO2 respirometry) and (Schmolz et al. (2002), calorimetry), and of young bees from (Stabentheiner et al. (2003a), Warburg O2 manometry).