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

Abstract

Flupyradifurone (FPF) is a novel systemic nAChR agonist that interferes with signal transduction in the central nervous system of sucking pests. Despite claims that FPF is potentially “bee-safe” by risk assessments, laboratory data have suggested that FPF has multiple sub-lethal effects on individual honey bees. Our study aimed to expand the studies to the effects of field-realistic concentration of FPF. We found a statistically significant decrease in the survival rate of honey bees exposed to FPF, whereas there were no significantly negative effects on larvae development durations nor foraging activity. In addition, we found that the exposed foragers showed significantly higher expression of ApidNT, CYP9Q2, CYP9Q3, and AmInR-2 compared to the CK group (control group), but no alteration in the gene expression was observed in larvae. The exposed newly emerged bees showed significantly higher expression of Defensin and ApidNT. These results indicate that the chronic exposure to the field-realistic concentration of FPF has negligible effects, but more important synergistic and behavioral effects that can affect colony fitness should be explored in the future, considering the wide use of FPF on crops pollinated and visited by honey bees.

Acute oral toxicity, apoptosis, and immune response in nurse bees (Apis mellifera) induced by flupyradifurone

“…Certain sublethal effects were not apparent or external, but they could cause molecular-level damage. Potential toxic effects of pesticides included changes in gene and protein expressions, as had been reported in previous studies (Wu et al, 2015;McKinstry et al, 2017;Tavares et al, 2019;Hou et al, 2020;Naggar and Paxton, 2020;Guo et al, 2021). In our previous research, after 6-day exposure on colonies and 12-h exposure of acute toxicity on newly emerged honey bees, FPF at field-realistic concentrations was reported to induce immune challenge, detoxification response, and olfactory learning deficits through different expression of certain genes in adult bees, especially in young bees (Wu et al, 2015;Guo et al, 2021).…”

“…Defensin was significantly upregulated in our results, which was consistent with that of newly emerged bees exposed by FPF at the colony level. The expression of defensin and apidNT was significantly higher than that of the control bees (Guo et al, 2021). Defensin was reported to be regulated by the Toll pathway in bees (Lourenço et al, 2018).…”

“…On the contrary, the expression of CYP9Q2 and CYP9Q3 was significantly upregulated in bee foragers, which were fed by FPF for 6 days. In addition, the survival rate of larvae in FPF-treated colonies was significantly lower than that in control colonies (Guo et al, 2021). Tan et al (2017) also reported that the exposure of FPF affected the learning and memory ability of adult bees (Apis cerana), which were fed with FPF at a field-realistic dose during the bee larval stage.…”

Impacts of Imidacloprid and Flupyradifurone Insecticides on the Gut Microbiota of Bombus terrestris

“…As for honeybee experiments, the 4 ppm flupyradifurone-treated group consumed 16% less nectar [52,53]. A previous study also reported that there were no negative effects on the larvae development and foraging activity of honeybees with 4 ppm flupyradifurone [54]. Due to the unique binding mode of flupyradifurone to nAChR, flupyradifurone is considered to have low-toxicity to the honeybee [21].…”

Butenolide Insecticide Flupyradifurone Affects Honey Bee Worker Antiviral Immunity and Survival

“…High doses of flupyradifurone can increase oxidative stress (30) and affect honey bee taste, cognition, and motor skills (31,32), while field-realistic doses can impair behavior and affect survival and immunity (33)(34)(35). Flupyradifurone exposure has been shown to increase expression of several honey bee immune genes (36), and lead to higher pathogen loads of the microsporidian Nosema ceranae in some colonies (37). Thus, as with neonicotinoids, it is imperative to consider not only acute lethal effects of flupyradifurone but also sublethal effects that may be more difficult to track.…”