6.2.1. Honey bee intra-hive temperature requirements

Despite considerable changes in ambient air temperature, honey bees typically maintain their brood nest between 32 and 36°C by adjusting their metabolism and by using a number of behavioural methods (Stabentheiner et al., 2010) to ensure optimal brood development. Nevertheless, outer edges of honey bee clusters can drop to as low as 10°C in winter when no brood is present (Seeley, 2010). Most laboratory studies maintained caged honey bees between 25-34°C (e.g. Webster, 1994; Higes et al., 2007; Paxton et al., 2007; Alaux et al., 2009), and 25 ± 2°C is recommended for testing acute oral toxicity of chemicals (OECD, 1998).