Impact of nutritional stress on the honeybee colony health

Abstract

Honeybees Apis mellifera are important pollinators of wild plants and commercial crops. For more than a decade, high percentages of honeybee colony losses have been reported worldwide. Nutritional stress due to habitat depletion, infection by different pests and pathogens and pesticide exposure has been proposed as the major causes. In this study we analyzed how nutritional stress affects colony strength and health. Two groups of colonies were set in a Eucalyptus grandis plantation at the beginning of the flowering period (autumn), replicating a natural scenario with a nutritionally poor food source. While both groups of colonies had access to the pollen available in this plantation, one was supplemented with a polyfloral pollen patty during the entire flowering period. In the short-term, colonies under nutritional stress (which consumed mainly E. grandis pollen) showed higher infection level with Nosema spp. and lower brood and adult bee population, compared to supplemented colonies. On the other hand, these supplemented colonies showed higher infection level with RNA viruses although infection levels were low compared to countries were viral infections have negative impacts. Nutritional stress also had long-term colony effects, because bee population did not recover in spring, as in supplemented colonies did. In conclusion, nutritional stress and Nosema spp. infection had a severe impact on colony strength with consequences in both short and long-term.

Diversity and Global Distribution of Viruses of the Western Honey Bee, Apis mellifera

“…For example, peaks of IAPV prevalence were observed from early spring (February-April) to early summer (June-July) depending on the year [131]. Such temporal dynamics of incidence of infectious diseases are a common phenomenon, generally attributed to variations in environmental factors (e.g., temperature and daylight in temperate regions) and the subsequent changes in resource availability affecting host behavior, density, brood production and possibly host immune competence to fight pathogen infections [132][133][134][135][136].…”

Towards Precision Nutrition: A Novel Concept Linking Phytochemicals, Immune Response and Honey Bee Health

“…They find that the performance of honey bee colonies (adult bee mass and brood) and biomarkers associated with adequate nutrition (e.g., vitellogenin) are positively influenced by their foraging proximity to CRP lands. In straight relationship with the work described above, Branchiccela et al [98] recently demonstrated that the nutritional state is related to the variety of pollen in the bees’ diet, and has a severe impact on bee colony strength and health, with both short and long-term consequences.…”

“…Besides, pollen activates nutrient-sensing and metabolic pathways, and influences the expression of genes involved in longevity, immune function, the production of certain antimicrobial peptides and pesticide detoxification [42,103]. At the same time, it is important to take into consideration that protein sources based on pollen mixes could be contaminated with different pesticides [98].…”

Dietary Contamination With Neonicotinoid (Clothianidin) Gradient Triggers Specific Dysbiosis Signatures of Microbiota Activity Along the Honeybee (Apis Mellifera) Digestive Tract

“…2, Supplementary Table S6). Previous studies highlighted how nutritional stress shapes the gut microbiota composition [113,114] inducing long term negative impacts on honeybee health [114]. Therefore, it is very likely that higher bioaccumulated clothianidin in younger bees (with an immature microbiota) would have long-term health effect.…”