title: Nutritional balance of essential amino acids and carbohydrates of the adult worker honeybee depends on age.
abstract: Dietary sources of essential amino acids (EAAs) are used for growth, somatic maintenance and reproduction. Eusocial insect workers such as honeybees are sterile, and unlike other animals, their nutritional needs should be largely dictated by somatic demands that arise from their role within the colony. Here, we investigated the extent to which the dietary requirements of adult worker honeybees for EAAs and carbohydrates are affected by behavioural caste using the Geometric Framework for nutrition. The nutritional optimum, or intake target (IT), was determined by confining cohorts of 20 young bees or foragers to liquid diets composed of specific proportions of EAAs and sucrose. The IT of young, queenless bees shifted from a proportion of EAAs-to-carbohydrates (EAA:C) of 1:50 towards 1:75 over a 2-week period, accompanied by a reduced lifespan on diets high in EAAs. Foragers required a diet high in carbohydrates (1:250) and also had low survival on diets high in EAA. Workers exposed to queen mandibular pheromone lived longer on diets high in EAA, even when those diets contained 5× their dietary requirements. Our data show that worker honeybees prioritize their intake of carbohydrates over dietary EAAs, even when overeating EAAs to obtain sufficient carbohydrates results in a shorter lifespan. Thus, our data demonstrate that even when young bees are not nursing brood and foragers are not flying, their nutritional needs shift towards a diet largely composed of carbohydrates when they make the transition from within-hive duties to foraging.
authors.affiliation: Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
authors.forename: Pier P
authors.initials: PP
authors.lastname: Paoli
authors.forename: Dion
authors.initials: D
authors.lastname: Donley
authors.forename: Daniel
authors.initials: D
authors.lastname: Stabler
authors.forename: Anumodh
authors.initials: A
authors.lastname: Saseendranath
authors.forename: Susan W
authors.initials: SW
authors.lastname: Nicolson
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Simpson
authors.forename: Geraldine A
authors.initials: GA
authors.lastname: Wright
mesh_terms: D000375:Aging; D000601:Amino Acids, Essential / Q000008:administration & dosage* / Q000378:metabolism; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D001516:Bees; D001522:Behavior, Animal / Q000502:physiology; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D005260:Female; D009751:Nutritional Requirements; D012098:Reproduction / Q000502:physiology; D012724:Sex Attractants / Q000502:physiology; D013395:Sucrose / Q000008:administration & dosage
chemical_list: D000601:Amino Acids, Essential; D004040:Dietary Carbohydrates; D012724:Sex Attractants; D013395:Sucrose