Fecha de publicación: 20/11/2024 Fuente: PubMed "bee pollen" Sci Total Environ. 2024 Nov 27;957:177626. doi: 10.1016/j.scitotenv.2024.177626. Online ahead of print.ABSTRACTBees are pollinators of native and cultivated plants around the world. However, several factors are contributing to the decrease in their populations in recent years, with emphasis on the increasing use of insecticides in agriculture. Thiamethoxam is a neonicotinoid neurotoxicant, which binds to nicotinic acetylcholine receptors, causing hyperexcitation, paralysis and death of insects. Although thiamethoxam's target is the nervous system, it can affect other organs through ingestion, such as the midgut, affecting non-target insects such as bees. Partamona helleri Friese (Hymenoptera: Apidae) is a stingless bee, pollinator of several native and cultivated botanical families, and can be exposed to sublethal concentrations of thiamethoxam. This study evaluated the side effects of chronic oral exposure to thiamethoxam on the midgut, oxidative stress and behavior of P. helleri workers. The bees were exposed orally, for 7 days, to the approximate sublethal concentration of thiamethoxam found in pollen grains (0.09 ng/g). The results demonstrated changes in the midgut epithelium of workers treated with thiamethoxam, such as cytoplasmic vacuolization, cellular protrusions, increased apocrine transfer, mitochondrial damage, decreased proteins and neutral polysaccharides and the presence of cells undergoing autophagy and apoptosis. Sublethal concentration of thiamethoxam also induced oxidative stress, evidenced by changes in the activities of detoxification enzymes and antioxidant markers. Finally, thiamethoxam affects the bee's behavior, driving the distance covered and walking speed of this insect. The results indicate that the exposure of P. helleri workers to sublethal concentration of thiamethoxam have negative impacts upon midgut morphology and physiology and behavioral traits.PMID:39566631 | DOI:10.1016/j.scitotenv.2024.177626