Effect of amino acid enriched diets on hemolymph amino acid composition in honey bees

Abstract

Amino acids (AAs) are an abundant class of nectar solutes, and they are involved in the nectar attractiveness to flower visitors. Among the various AAs, proline is the most abundant proteogenic AA, and γ‐amino butyric acid (GABA) and β‐alanine are the two most abundant non‐proteogenic AAs. These three AAs are known to affect insect physiology, being involved in flight metabolism and neurotransmission. The aim of this study was to investigate the effects of artificial diets enriched with either β‐alanine, GABA, or proline on consumption, survival, and hemolymph composition in honey bees belonging to two different ages and with different metabolism (i.e., newly emerged and foragers). Differences in feed intake among diets were not observed, while a diet enriched with β‐alanine improved the survival rate of newly emerged honey bees compared to the control group. Variations in the hemolymph AA concentrations occurred only in newly emerged honey bees, according to the diet and the time of hemolymph sampling. A greater susceptibility of young honey bees to enriched diets than older honey bees was observed. The variations in the concentrations of hemolymph AAs reflect either the accumulation of dietary AAs or the existence of metabolic pathways that may lead to the conversion of dietary AAs into different ones. This investigation could be an initial contribution to studying the complex dynamics that regulate hemolymph AA composition and its effect on honey bee physiology.

Enhancing Honey Bee Health: Evaluating Pollen Substitute Diets in Field and Cage Experiments

“…In a separate study, while β-alanine, GABA, citrulline, ornithine, and taurine did not affect nectar palatability, β-alanine and GABA were observed to improve learning and memory functions in honey bees [47]. Additionally, β-alanine was found to improve the survival rate of newly emerged honey bees [48]. In the present study, alanine, asparagine, and the total amino acid content exhibited a significant positive correlation with hygienic behavior, while leucine exhibited a significant negative correlation with hygienic behavior.…”