Life expectancy and onset of foraging in the honeybee (Apis mellifera)

Abstract

Predictions that precocious foraging in honeybee workers is a result of shortening of their life expectancy were tested in both laboratory and field experiments. In the laboratory experiment, we assessed the impact of anaesthesia with CO 2 and infection with Nosema apis on the lifespan of workers. In the field experiment, the age at onset of foraging was observed in groups of workers with different expected lifespans. In both the experiments, workers originating from one queen inseminated with the semen of one drone were divided into five groups. The first group was anaesthetized with CO 2 on the first day of life. Workers from the other three groups were individually inoculated with a constant number of N. apis spores on the 1st, 6th and 11th days of life. Workers from the fifth control group were neither treated with CO 2 nor inoculated in any way. Both the laboratory and field experiments revealed that anaesthetized and infected workers had shorter expected lifespans compared to control bees. Amongst infected workers, those inoculated earlier in life survived for a significantly shorter period of time in comparison to those infected later in life. In agreement with the expectation, the field experiment showed that anaesthetized and infected workers with shorter expected lifespan start foraging earlier than control workers. Amongst the infected workers, age at inoculation correlated with age at onset of foraging. This means that short-lived workers complete safe nest tasks and begin riskier foraging earlier in life. Our results provide a strong support for the hypothesis that the division of labour in eusocial insects is a consequence of the different expected worker lifespan and different risk associated with their tasks; however, they do not contradict other existing explanations.

Covert deformed wing virus infections have long-term deleterious effects on honeybee foraging and survival

“…Indeed, in the case of DWV, a direct influence on the behaviour of its host is not unlikely, given that DWV particles have previously been found in the mushroom bodies-a key higher brain centre of these insects [31] (but see [34] for a study where no behavioural effects were found). Irrespective of these possible adaptive causes, it is clear that precocious foraging would have a major effect on colony well-being, as premature foraging partially depletes the nurse bee population [63] and disrupts various activities inside the hive [64][65][66], and rapid behavioural maturation has been shown to strongly accelerate the failure of stressed honeybee colonies [63].…”

Reproduction, social behavior, and aging trajectories in honeybee workers

“…However, the documented relation between behavior and life expectancy is correlative. Behavior may influence life expectancy (Rueppell et al 2007;Amdam et al 2009), but remaining life expectancy may also be a determinant of social behavior (Woyciechowski and Kozlowski 1998;Woyciechowski and Moron 2009;Kuszewska and Woyciechowski 2013). Regardless of causality, we also found evidence for an interaction between the social environment and the relation between social behavior and life expectancy.…”

Weight of evidence evaluation of a network of adverse outcome pathways linking activation of the nicotinic acetylcholine receptor in honey bees to colony death

“…The act of foraging is a perilous and metabolically challenging task that is typically carried out by worker bees in the later stages of life (Woyciechowski and Moroń, 2009). However, the timing of the role change from hive bee to forager can vary depending on the needs of the colony.…”

“…In addition, precocious foraging is correlated with shorter lifespans. Therefore, bees that forage earlier tend to do so at the expense of their longevity which could impact overall colony resource acquisition and productivity (Woyciechowski and Moroń, 2009). However, the relationship may be complex given that with seasonal variation, food availability, predation pressures, and adverse weather conditions that promote greater in-hive activity, older foragers can reverse their behavior, regenerate hypopharyngeal glands, and assume roles within the hive (Huang and Robinson, 1996).…”