Field rates of Sivanto™ (flupyradifurone) and Transform® (sulfoxaflor) increase oxidative stress and induce apoptosis in honey bees (Apis mellifera L.)

Abstract

Pesticide exposures can have detrimental impacts on bee pollinators, ranging from immediate mortality to sub-lethal impacts. Flupyradifurone is the active ingredient in Sivanto™ and sulfoxaflor is the active ingredient in Transform ®. They are both relatively new insecticides developed with an intent to reduce negative effects on bees, when applied to bee-attractive crops. With the growing concern regarding pollinator health and pollinator declines, it is important to have a better understanding of any potential negative impacts, especially sublethal, of these pesticides on bees. This study reports novel findings regarding physiological stress experienced by bees exposed to field application rates of these two insecticides via a Potter Tower sprayer. Two contact exposure experiments were conducted-a shorter 6hour study and a longer 10-day study. Honey bee mortality, sugar syrup and water consumption, and physiological responses (oxidative stress and apoptotic protein assays) were assessed in bees exposed to Sivanto™ and Transform ® , and compared to bees in control group. For the longer, 10-day contact exposure experiment, only the Sivanto™ group was compared to the control group, as high mortality recorded in the sulfoxaflor treatment group during the shorter contact exposure experiment, made the latter group unfeasible to test in the longer 10-days experiment. In both the studies, sugar syrup and water consumptions were significantly different between treatment groups and controls. The highest mortality was observed in Transform ® exposed bees, followed by the Sivanto™ exposed bees. Estimates of reactive oxygen/nitrogen species indicated significantly elevated oxidative stress in both pesticide treatment groups, when compared to controls. Caspase-3 protein assays, an indicator of onset of apoptosis, was also significantly higher in the pesticide treatment groups. These differences were largely driven by post exposure duration, indicating sublethal impacts. Further, our findings also emphasize the need to revisit contact exposure impacts of Sivanto™, given the sub-lethal impacts and mortality observed in our long-term (10-day) contact exposure experiment.

The protective role of resveratrol against sulfoxaflor‐induced toxicity in testis of adult male rats

“…Our results revealed that daily oral intake of Sulfx for 28 consecutive days at low (79.5 mg/kg) and high dose (205 mg/kg) expert toxic influences on the male rat reproductive organs indicated by the high content of testicular MDA, GSSG, and NOx versus the reduction in GSH content in a dose‐dependent manner. These data suggested elevated LPO and reflected the occurrence of oxidative stress due to Sulfx administration in the testis, in agreement with the results reported by Chakrabarti et al 45 who reported increased oxidative stress in bees exposed to Transform® (active ingredient sulfoxaflor). Other investigations correlated oxidative stress and increased production of ROS and reactive nitrogen species (NS) to neonicotinoid toxicity 46–48 .…”

“…Caspases are crucial mediators of apoptosis, among them caspase‐3 is a frequently activated protease that catalyzes the cleavage of several structural and regulatory proteins essential for cell survival and maintenance. Its activation increases under pesticide stress in all organisms 45 . An increase in the occurrence of germ cell apoptosis is commonly reported following toxicant exposure.…”

The novel insecticides flupyradifurone and sulfoxaflor do not act synergistically with viral pathogens in reducing honey bee (Apis mellifera) survival but sulfoxaflor modulates host immunocompetence

“…Hesselbach et al (2020) recently showed that chronic exposure to FPF can lead to the premature onset of foraging in A. mellifera. Additionally, exposure to field rates of Sivanto TM (FPF) and Transform â (SULF) has also recently been shown to increase oxidative stress and induce apoptosis in A. mellifera (Chakrabarti et al, 2020). Studies have yet to investigate interactions between sublethal doses of these two novel pesticides and viral pathogens that affect honey bee health.…”

The influence of recent Brazilian policy and legislation on increasing bee mortality

“…In Brazil, six products were also recently released based on the active ingredient sulfoxaflor, a new sulfoximine class insecticide, and three more containing lambda-cyhalothrin (pyrethroid) and sulfoxaflor, totaling nine products using that active ingredient (Agrofit, 2019). Interestingly, sulfoxaflor usage has been related to several sublethal impacts and increase in bee mortality worldwide (Siviter, Brown & Leadbeater, 2018;Chakrabarti et al, 2020;Azpiazu et al, 2021). After many member states of the European Union have banned the use of neonicotinoids insecticides such as imidacloprid, clothianidin, and thiamethoxam outside greenhouse structures, sulfoxaflor arrived on the market as a differentiated neonicotinoid, because it acts on the insect nicotinic acetylcholine receptor (nAChR) in a distinct manner relative to neonicotinoids (Millot et al, 2017).…”