4.1.8. Environment surrounding source colonies used to obtain adult workers for laboratory experiments
Source colonies should not be located in intensive agricultural areas with high agricultural chemical use or low bee-plant diversity because of potential sub-lethal or synergistic effects of residues (Wu et al., 2011; Pettis et al., 2012) and the importance of nutrition to honey bee vitality (Brodschneider and Crailsheim, 2010), respectively. Additionally, knowledge of neighbouring apiaries is useful because of the potential for disease transmission. Note that honey bee poisoning can also occur in non-agricultural areas (e.g. natural or urban areas), normally because of misuse of pesticides on attractive flowering garden plants. These toxic pesticides used during blooming may cause important honey bee loss, although their residues may not necessarily will be found in hive matrices as individuals may die before returning to the colony. These deaths can alter the age profile of workers available for collection for experiments. Therefore, one should not collect workers from colonies that experience unexpected depopulation or abnormal honey bee mortality in front of the hive. Although costly, analyses of honey bees and their products (especially bee bread) can be used to quantify chemical residues within colonies. Local information on pesticide applications may also be gleaned from agricultural pesticide-use databases when they are available.
Vegetation surveys can be performed within normal worker foraging distances from the colony – within a 2 km radius of the hive (Winston, 1987) – to identify major nectar and pollen producing plants. Careful inspection of bee bread will also determine diversity of floral sources. This can be performed by visualizing pollen grain morphology using microscopy, or more crudely by colour differentiation (see Delaplane et al. (2013) in the pollination paper of the BEEBOOK for details on identifying plant species using pollen grains).