title: The geometric framework for nutrition reveals interactions between protein and carbohydrate during larval growth in honey bees.
abstract: In holometabolous insects, larval nutrition affects adult body size, a life history trait with a profound influence on performance and fitness. Individual nutritional components of larval diets are often complex and may interact with one another, necessitating the use of a geometric framework for elucidating nutritional effects. In the honey bee,Apis mellifera, nurse bees provision food to developing larvae, directly moderating growth rates and caste development. However, the eusocial nature of honey bees makes nutritional studies challenging, because diet components cannot be systematically manipulated in the hive. Usingin vitrorearing, we investigated the roles and interactions between carbohydrate and protein content on larval survival, growth, and development inA. melliferaWe applied a geometric framework to determine how these two nutritional components interact across nine artificial diets. Honey bees successfully completed larval development under a wide range of protein and carbohydrate contents, with the medium protein (∼5%) diet having the highest survival. Protein and carbohydrate both had significant and non-linear effects on growth rate, with the highest growth rates observed on a medium-protein, low-carbohydrate diet. Diet composition did not have a statistically significant effect on development time. These results confirm previous findings that protein and carbohydrate content affect the growth ofA. melliferalarvae. However, this study identified an interaction between carbohydrate and protein content that indicates a low-protein, high-carb diet has a negative effect on larval growth and survival. These results imply that worker recruitment in the hive would decline under low protein conditions, even when nectar abundance or honey stores are sufficient.
authors.affiliation: Department of Biological Sciences, North Dakota State University, Fargo, ND 58108-6050, USA bryan.r.helm@ndsu.edu.
authors.forename: Bryan R
authors.identifier: http://orcid.org/0000-0003-3386-7842
authors.initials: BR
authors.lastname: Helm
authors.affiliation: Department of Biological Sciences, North Dakota State University, Fargo, ND 58108-6050, USA.
authors.forename: Garett P
authors.initials: GP
authors.lastname: Slater
authors.affiliation: Agricultural Research Service - Insect Genetics and Biochemistry, Red River Valley Agricultural Research Center, United States Department of Agriculture, Fargo, ND 58102, USA.
authors.forename: Arun
authors.initials: A
authors.lastname: Rajamohan
authors.affiliation: Agricultural Research Service - Insect Genetics and Biochemistry, Red River Valley Agricultural Research Center, United States Department of Agriculture, Fargo, ND 58102, USA.
authors.forename: George D
authors.initials: GD
authors.lastname: Yocum
authors.affiliation: Department of Biological Sciences, North Dakota State University, Fargo, ND 58108-6050, USA.
authors.forename: Kendra J
authors.initials: KJ
authors.lastname: Greenlee
authors.affiliation: Department of Biological Sciences, North Dakota State University, Fargo, ND 58108-6050, USA.
authors.forename: Julia H
authors.initials: JH
authors.lastname: Bowsher
keywords: Apis mellifera; Diet quality; Geometric framework; Growth; Honey bee; Larva; Nutrition