Impacts of Dietary Phytochemicals in the Presence and Absence of Pesticides on Longevity of Honey Bees (Apis mellifera)

Abstract

Because certain flavonols and phenolic acids are found in pollen and nectar of most angiosperms, they are routinely ingested by Apis mellifera, the western honey bee. The flavonol quercetin and the phenolic acid p-coumaric acid are known to upregulate detoxification enzymes in adult bees; their presence or absence in the diet may thus affect the toxicity of ingested pesticides. We conducted a series of longevity assays with one-day-old adult workers to test if dietary phytochemicals enhance longevity and pesticide tolerance. One-day-old bees were maintained on sugar syrup with or without casein (a phytochemical-free protein source) in the presence or absence of quercetin and p-coumaric acid as well as in the presence or absence of two pyrethroid insecticides, bifenthrin and β-cyfluthrin. Dietary quercetin (hazard ratio, HR = 0.82), p-coumaric acid (HR = 0.91) and casein (HR = 0.74) were associated with extended lifespan and the two pyrethroid insecticides, 4 ppm bifenthrin (HR = 9.17) and 0.5 ppm β-cyfluthrin (HR = 1.34), reduced lifespan. Dietary quercetin enhanced tolerance of both pyrethroids; p-coumaric acid had a similar effect trend, although of reduced magnitude. Casein in the diet appears to eliminate the life-prolonging effect of p-coumaric acid in the absence of quercetin. Collectively, these assays demonstrate that dietary phytochemicals influence honey bee longevity and pesticide stress; substituting sugar syrups for honey or yeast/soy flour patties may thus have hitherto unrecognized impacts on adult bee health.

Behavioral responses of honey bees (Apis mellifera) to natural and synthetic xenobiotics in food

“…The phenolic acid p- coumaric acid, a constituent of many honeys, upregulates both detoxification genes and immunity genes in larval and adult honey bees; bees consuming p -coumaric acid in sugar diet were capable of 60% higher rates of metabolism of the organophosphate acaricide coumaphos than bees consuming sugar diet alone 12 , 13 . Quercetin, a flavonol found in many honeys, essentially all pollen, and in propolis in many parts of the world, also upregulates at least 12 genes encoding cytochrome P450 monooxygenases, including CYP9Q1, CYP9Q2, and CYP9Q3, which detoxify both tau-fluvalinate and coumaphos 14 and enhances longevity of workers exposed to the pyrethroid insecticide β-cyfluthrin 15 . Additionally, a sucrose diet containing both quercetin and p -coumaric acid enhanced the longevity of bees exposed to bifenthrin 15 .…”

“…Quercetin, a flavonol found in many honeys, essentially all pollen, and in propolis in many parts of the world, also upregulates at least 12 genes encoding cytochrome P450 monooxygenases, including CYP9Q1, CYP9Q2, and CYP9Q3, which detoxify both tau-fluvalinate and coumaphos 14 and enhances longevity of workers exposed to the pyrethroid insecticide β-cyfluthrin 15 . Additionally, a sucrose diet containing both quercetin and p -coumaric acid enhanced the longevity of bees exposed to bifenthrin 15 .…”

Biphasic concentration-dependent interaction between imidacloprid and dietary phytochemicals in honey bees (Apis mellifera)

“…Once a sufficient number of one-day-old bees emerged from the frames, for both the LC 50 and longevity assay, they were transferred into closed clear 266-mL plastic cups with multiple ventilation holes and two larger holes for the insertion of food and water feeder tubes. The general arrangement and positioning of experimental cages and feeders were modified from our previous research [ 46 ]. For the duration of the experiment, caged bees were kept in a dark incubator room at 34°C and 50% humidity.…”

“…Accordingly, the possibility exists that co-occurring dietary phytochemicals alter behavioral or physiological responses of honey bees to imidacloprid. Quercetin reduces the acute toxicity of the pyrethroid tau-fluvalinate [ 39 ], and both quercetin and p- coumaric acid increase longevity of honey bees in the presence of two pyrethroids, β-cyfluthrin and bifenthrin [ 46 ]. All three of these pyrethroid insecticides are metabolized by members of the CYP9Q subfamily, suggesting that amelioration of pesticide toxicity by p- coumaric acid and quercetin is due to induction of these enzymes.…”

Novel Insights into Dietary Phytosterol Utilization and Its Fate in Honey Bees (Apis mellifera L.)

“…Research has shown that well-nourished honey bees survive longer, are better able to resist biotic and abiotic stressors and have enhanced immunity [4][5][6][7][8]. For all bee pollinators, the two principal dietary resources are pollen (their source of proteins, lipids phytochemicals and vitamins) and nectar (their primary source of carbohydrates and also vital phytochemicals) [4,5,[9][10][11][12]. Pollen is additionally crucial because it is the only natural dietary source of important micronutrients for bees, for example: phytosterols [12].…”