Nuances in diet quality and quantity influence phenotypic dimorphism during honey bee (Apis mellifera) caste determination

Authors: SLATER, GARETT - North Dakota State University; Yocum, George; BOWSHER, JULIA - North Dakota State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/15/2015
Publication Date: N/A
Citation: N/A

Interpretive Summary: Nutrition intake during the larval stage of holometabolous insect’s influences and fuels growth throughout metamorphosis. In social insects, differences in larval nutrition can regulate a profound reproductive division of labor. Provisioning by nurse bees differs between worker-destined and queen-destined larvae, and drives the phenotypic dimorphism. Many studies have evaluated the dietary factors determining caste, such as individual macronutrients and overall quantity. Due to insufficiencies in previous studies, a myriad of research has concluded the “caste determining factors” such as specific dietary quality and quantity, but these reports conflict with each other. Because nutritional factors determining queen-worker caste is enigmatic, a study with careful quantity and quality manipulation is needed. We evaluated both dietary quantity and quality on phenotypic dimorphism by using the geometric framework. This method is powerful because it gauges the interactions among a wide variety of nutritional components and it allows us to evaluate if either specific dietary components, or multiple dietary interactions determine caste in honey bees. We manipulated our standard in vitro rearing diet by varying both the macronutrient and quantity components. By following these developing bees to eclosion, we were able to evaluate phenotypic differences between castes such as number of ovariole number, weight, spermetheca size, mandible structure, basitarsus, width and length of head. We then used a principal component analysis(PCA) to classify these bees as queens, workers or intercastes by comparing to hive bees. This research not only allows us to further research the cellular mechanisms involved in caste determination, but also we can further study the physiology of both workers and queens.

Technical Abstract: Nutrition intake during the larval stage of holometabolous insect’s influences and fuels growth throughout metamorphosis. In social insects, differences in larval nutrition can regulate a profound reproductive division of labor. Provisioning by nurse bees differs between worker-destined and queen-destined larvae, and drives the phenotypic dimorphism. Many studies have evaluated the dietary factors determining caste, such as individual macronutrients and overall quantity. Due to insufficiencies in previous studies, a myriad of research has concluded the “caste determining factors” such as specific dietary quality and quantity, but these reports conflict with each other. Because nutritional factors determining queen-worker caste is enigmatic, a study with careful quantity and quality manipulation is needed. We evaluated both dietary quantity and quality on phenotypic dimorphism by using the geometric framework. This method is powerful because it gauges the interactions among a wide variety of nutritional components and it allows us to evaluate if either specific dietary components, or multiple dietary interactions determine caste in honey bees. We manipulated our standard in vitro rearing diet by varying both the macronutrient and quantity components. By following these developing bees to eclosion, we were able to evaluate phenotypic differences between castes such as number of ovariole number, weight, spermetheca size, mandible structure, basitarsus, width and length of head. We then used a principal component analysis(PCA) to classify these bees as queens, workers or intercastes by comparing to hive bees. This research not only allows us to further research the cellular mechanisms involved in caste determination, but also we can further study the physiology of both workers and queens.