5. Temperature, radiation and humidity measurement in honey bees
Temperature is a decisive parameter in honey bee development, physiology and behaviour, at the individual as well as at the social level (Heinrich, 1993). Larval respiration and growth is strongly dependent on temperature (Petz et al., 2004). A high speed of development is guaranteed via social regulation of brood temperature in the range of 33-36 °C (Kleinhenz et al., 2003; Stabentheiner et al., 2010). Low temperatures during pupal development may impair learning and cause significant differences in the behaviour of adult bees (Tautz et al., 2003; Becher et al., 2009). Colony temperature also affects the basal metabolism of hive bees (Stabentheiner et al., 2003a; Kovac et al., 2007). Social thermoregulation allows for overwintering of colonies in cold climates (Stabentheiner et al., 2003b). During the foraging cycle honey bees are always endothermic, which means that they display a high oxygen consumption (and thus energy turnover) to keep their body temperature well above the ambient level (Heinrich, 1993; Stabentheiner et al.; 1995; Kovac and Schmaranzer, 1996; Roberts and Harrison, 1999; Kovac et al., 2010; Stabentheiner et al., 2012). Measurement of honey bee body and colony temperature and of environmental parameters requires care to achieve correct results. The following summary is meant as a guide to avoid the main pitfalls of honey bee body temperature and environmental parameter measurement.