Consequences of a short time exposure to a sublethal dose of Flupyradifurone (Sivanto) pesticide early in life on survival and immunity in the honeybee (Apis mellifera)

Abstract

Dramatic losses of pollinating insects have become of global concern, as they threaten not only key ecosystem services but also human food production. Recent research provided evidence that interactions between ecological stressors are drivers of declining pollinator health and responsible for observed population collapses. We used the honeybee Apis mellifera and conducted a series of experiments to test for long-term effects of a single short exposure to the agricultural pesticide flupyradifurone to a second environmental stressor later in life. To do this, we exposed individuals during their larval development or early adulthood to sublethal dosages of flupyradifurone (0.025 μg for larvae and 0.645 μg for imagos), either pure or as part of an agricultural formulation (Sivanto). We afterwards exposed bees to a second ecological stressor infecting individuals with 10,000 spores of the fungal gut parasite Nosema ceranae. We found that pesticide exposures significantly reduced survival of bees and altered the expression of several immune and detoxification genes. The ability of bees to respond to these latter effects differed significantly between colonies, offering opportunities to breed bees with elevated levels of pesticide tolerance in the future. We conclude that short episodes of sublethal pesticide exposures during development are sufficient to trigger effects later in life and could therefore contribute to the widespread declines in bee health.

The Effects of Exposure to Flupyradifurone on Survival, Development, and Foraging Activity of Honey Bees (Apis mellifera L.) under Field Conditions

“…Results showed that chronic exposed to FPF for six days during larval stage significantly reduced the survival rate of the larvae of A. mellifera ( Figure 1 ), which was in line with the previous study reported by Al Naggar et al [ 26 ]. However, Campbell et al demonstrated no colony-level impacts of FPF on the number of bees, eggs, brood, or colony weight [ 21 ].…”

“…The number of honey bee eggs, larvae, pupae, adults or dead bee in the cells were observed and recorded every 12 h. If the cell was newly emptied, the larvae and pupa were considered dead. [ 26 ]. The developmental time from egg-hatching until emergence was also recorded for each marked bee.…”

“…For Apis cerana , chronic exposure to FPF impaired olfactory learning in both larval and adult bees, and bee larvae were more sensitive to FPF [ 25 ]. It has been demonstrated that a sub-lethal dose of FPF induced a significant reduction in adult emergence [ 26 ]. In addition, interaction with other environmental stressors may well make FPF more detrimental to honey bees than FPF examined as a single factor.…”

“…The combination of FPF and a common fungicide (propiconazole) increased abnormal behaviors of both in-hive and forager bees even at FPF field-realistic concentration (worst-case scenarios) [ 28 ]. Co-exposure with FPF and a bee parasite Nosema ceranae can increase mortality and alter the expression of immune and detoxification related genes in honey bees [ 26 ]. Taken together, the information suggests that FPF poses a potential risk to honey bees, despite FPF being considered as “bee safe” by the EPA.…”

Flupyradifurone reduces nectar consumption and foraging but does not alter honey bee recruitment dancing

“…FPF is reported to be relatively safe for the European honey bees, Apis mellifera, (Campbell et al, 2016;Glaberman and White, 2014), but there is growing evidence of detrimental effects for beneficial pollinators such as honey bees, which are widely used to pollinate agricultural crops treated with FPF. This pesticide can reduce bee survival and is associated with altered expression of bee immune and detoxification genes (Naggar and Baer, 2019). FPF also has multiple behavioral effects.…”