4.1.9. Weather before and during collection of adult workers for laboratory experiments
Weather events prior to honey bee collection can have a dramatic influence on colony strength and health. Periods of dearth or drought can greatly reduce food reserves within colonies (Schmickl and Crailsheim, 2001); whereas, prolonged periods of unfavourable flying conditions (e.g. rain, snow, wind) can confine workers to colonies for extended periods, and may promote overall colony stress (Schmickl and Crailsheim, 2007) and intra-colony disease transmission (Fries, 1993).
Current weather can also greatly affect flying patterns, and therefore potentially influence worker collection. Age polyethism observed in honey bees typically dictates that older individuals perform tasks outside of the colony, such as ventilating and guarding the colony, as well as collecting food (Winston, 1987). Therefore during unfavourable conditions a high number of older individuals will be present in the colony.
Both temperature and solar radiation influence foraging patterns (Burrill and Dietz, 1981). For example, foraging activity is positively related to temperature between 12-20°C (below 12°C honey bees typically do not search for food). Similarly, a positive relationship between foraging and solar radiation exists at low radiation intensities (i.e. <0.66 langley (common unit of energy distribution for measuring solar radiation); the opposite occurs at high intensities). Expectedly, higher winds and rainfall also results in decreasing foraging activity, and therefore a greater number of older individuals in the colony (Winston, 1987). Sunny, warm weather conditions are optimal for collecting workers for experiments because fewer constraints are likely to limit the ability of workers to perform their required tasks. Regardless of weather, current conditions during collection, or unusual weather events prior to collection that may influence the nature of worker collection, should always be noted.