Enantioselective Olfactory Effects of the Neonicotinoid Dinotefuran on Honey Bees (Apis mellifera L.)

Abstract

Sublethal exposure to neonicotinoids affects honey bee olfaction, but few studies have investigated the sublethal effects of the enantioselective neonicotinoid dinotefuran on honey bee olfaction. This study assessed the sublethal olfactory toxicity of dinotefuran enantiomers to honey bees. Compared to R-dinotefuran, S-dinotefuran had higher acute oral toxicity, sucrose sensitivity effects, octopamine concentrations, lower learning ability, and memory effects on honey bees. Highthroughput circular RNA sequencing of the honey bee brain revealed that R-dinotefuran caused more gene regulatory changes than S-dinotefuran. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses demonstrated that the SERCA, Kca, and Maxik genes may be related to the enantioselective effects of dinotefuran isomers on honey bee olfaction. These results indicated that the current ecotoxicological safety knowledge about chiral dinotefuran effects on honey bees should be amended.

Field‐realistic neonicotinoid exposure has sub‐lethal effects on non‐Apis bees: A meta‐analysis

“…In addressing whether the observed effects were consistent across different types of neonicotinoids, we found largely similar effects across the different insecticides but some, such as acetamiprid and dinotefuran, were either absent, or poorly represented within our analysis. Research with honeybees has demonstrated sub‐lethal effects of both acetamiprid and dinotefuran (Liu et al, 2019; Shi et al, 2020), but whether these effects are consistent across other bee species is unclear. Given that acetamiprid is still licenced for use in the EU, and that both insecticides are used globally, more research on their impact on non‐ Apis bees is clearly required.…”

Identification of long noncoding RNAs reveals the effects of dinotefuran on the brain in Apis mellifera (Hymenopptera: Apidae)

“…The nAChRs are the targets of neonicotinoid insecticides [ 2 ], and five nAChR subunits (nAChRα4, the putative target of TCONS_00040953; nAChRα7, the target of XR_001705519.2; nAChRα8, the target of TCONS_00031755, TCONS_00031757 and TCONS_00031758; nAChRα9, the target of XR_003306308.1 and XR_003304779.1; and nAChRβ4, the target of XR_001705519.2) were separately investigated for their effects in trans . The induction of nAChRs can result in distinct effects; for instance, exposure to sublethal dinotefuran doses can affect olfaction, basic motor function and postural control in honey bees [ 12 , 42 , 43 ]. Defensin genes, which play an important role in the innate humoral immune system of honey bees and are associated with responses against G- and, G+ bacteria and fungi, showed significantly lower expression in the dinotefuran-treated group [ 44 , 45 ].…”

“…Dinotefuran residues have been detected in nectar, pollen and bee bread, with measured residues in pollen of approximately 147 ng/g [ 11 ]. Studies have shown that treatment with a sublethal dose of dinotefuran affects olfaction, octopamine concentrations, learning and homing ability in honey bees [ 12 , 13 ].…”

Toxicological Effect and Molecular Mechanism of the Chiral Neonicotinoid Dinotefuran in Honeybees

“…Subsequent studies have shown that mitochondrial DNA damage may lead to disturbances in energy metabolism during neonicotinoid exposure and negatively affect the overwinter survival of honeybees . In addition, under the environmental-relevant exposure, neonicotinoids may have negative effects on the orientation activity, immune system, learning, memory formation, and communication of honeybees . Once bees have lost learning and memory retention ability, their health would be at risk.…”