BackgroundIn honey bee colony, the brood is able to manipulate and chemically control the workers in order to sustain their own development. A brood ester pheromone produced primarily by old larvae (4 and 5 days old larvae) was first identified as acting as a contact pheromone with specific effects on nurses in the colony. More recently a new volatile brood pheromone has been identified: E-β-ocimene, which partially inhibits ovary development in workers.Methodology and Principal FindingOur analysis of E-β-ocimene production revealed that young brood (newly hatched to 3 days old) produce the highest quantity of E-β-ocimene relative to their body weight. By testing the potential action of this molecule as a non-specific larval signal, due to its high volatility in the colony, we demonstrated that in the presence of E-β-ocimene nest workers start to forage earlier in life, as seen in the presence of real brood.Conclusions/SignificanceIn this way, young larvae are able to assign precedence to the task of foraging by workers in order to increase food stores for their own development. Thus, in the complexity of honey bee chemical communication, E-β-ocimene, a pheromone of young larvae, provides the brood with the means to express their nutritional needs to the workers.
Honeybee workers express a pronounced age-dependent polyethism switching from various indoor duties to foraging outside the hive. This transition is accompanied by tremendous changes in the sensory environment that sensory systems and higher brain centers have to cope with. Foraging and age have earlier been shown to be associated with volume changes in the mushroom bodies (MBs). Using age- and task-controlled bees this study provides a detailed framework of neuronal maturation processes in the MB calyx during the course of natural behavioral maturation. We show that the MB calyx volume already increases during the first week of adult life. This process is mainly driven by broadening of the Kenyon cell dendritic branching pattern and then followed by pruning of projection neuron axonal boutons during the actual transition from indoor to outdoor duties. To further investigate the flexible regulation of division of labor and its neuronal correlates in a honeybee colony, we studied the modulation of the nurse-forager transition via a chemical communication system, the primer pheromone ethyl oleate (EO). EO is found at high concentrations on foragers in contrast to nurse bees and was shown to delay the onset of foraging. In this study, EO effects on colony behavior were not as robust as expected, and we found no direct correlation between EO treatment and synaptic maturation in the MB calyx. In general, we assume that the primer pheromone EO rather acts in concert with other factors influencing the onset of foraging with its effect being highly adaptive.
E-β-ocimene / ovary development / pheromone / brood / Apis mellifera Note scientifique sur une nouvelle phéromone modificatrice volatile qui inhibe le développement ovarien des abeilles, le E-β-ocimene.
564A. Maisonnasse et al.
Eine wissenschaftliche Notiz über E-β-ocimene, ein neues flüchtiges Primer-Pheromon, das dieOvarentwicklung der Honigbienen hemmt.
Honeybee colony survival strongly relies on the queen to overcome worker losses exposed to combined stressors like pesticides and parasites. Queen’s capacity to withstand these stressors is however very little known. The effects of the common neonicotinoid pesticide imidacloprid in a chronic and sublethal exposure together with the wide distributed parasite Nosema ceranae have therefore been investigated on queen’s physiology and survivorship in laboratory and field conditions. Early physiological changes were observed on queens, particularly the increase of enzyme activities (catalase [CAT] and glutathione-S-transferase [GST] in the heads) related to protective responses to xenobiotics and oxidative stress against pesticide and parasite alone or combined. Stressors also alter the activity of two other enzymes (carboxylesterase alpha [CaE α] and carboxylesterase para [CaE p] in the midguts) involved in metabolic and detoxification functions. Furthermore, single and combined effects of pesticide and parasite decrease survivorship of queens introduced into mating hives for three months. Because colony demographic regulation relies on queen’s fertility, the compromise of its physiology and life can seriously menace colony survival under pressure of combined stressors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.