Sublethal exposure to thiamethoxam and pyraclostrobin affects the midgut and Malpighian tubules of the stingless bee Frieseomelitta varia (Hymenoptera: Apidae: Meliponini).

Autor: da Silva JA; Departament of General and Applied Biology, Institute of Biosciences (UNESP-SP), Rio Claro, Brazil. jaqueline.aparecida-silva@unesp.br., Farder-Gomes CF; Department of Natural Sciences and Mathematics, Federal University of São Carlos, (UFSCar, SP), Araras, Brazil., Barchuk AR; Department of Cellular and Developmental Biology, Institute of Biomedical Sciences, Federal University of Alfenas (UNIFAL-MG), Alfenas, Brazil., Malaspina O; Departament of General and Applied Biology, Institute of Biosciences (UNESP-SP), Rio Claro, Brazil., Nocelli RCF; Department of Natural Sciences and Mathematics, Federal University of São Carlos, (UFSCar, SP), Araras, Brazil.
Jazyk: angličtina
Zdroj: Ecotoxicology (London, England) [Ecotoxicology] 2024 Oct; Vol. 33 (8), pp. 875-883. Date of Electronic Publication: 2024 Jul 13.
DOI: 10.1007/s10646-024-02786-4
Abstrakt: The stingless bee Frieseomelitta varia Lepeletier 1836 (Hymenoptera: Apidae) is an essential pollinator in natural and agricultural ecosystems in the Neotropical region. However, these bees may be exposed to pesticides during foraging, which can affect both individuals and their colonies. One example comes from the use of pyraclostrobin (a fungicide) and thiamethoxam (an insecticide) for pest control in pepper crops, which F. varia visits. This study aimed to evaluate the isolated and combined sublethal effects of thiamethoxam (TMX) (0.000543 ng a.i./µL) and pyraclostrobin (PYR) (1.5 ng i.a./µL) on the morphology of the midgut and Malpighian tubules of F. varia workers. Results showed that both pesticides, regardless of the exposure time (through feeding during 48 h or 96 h), disturbed the morphology of the analyzed organs. Specifically, F. varia exposed orally to sublethal concentrations of thiamethoxam and pyraclostrobin, either alone or in combination, exhibited a higher rate of damage to the midgut (e.g., vacuolization, apocrine secretion, and cellular elimination) compared to the bees in the control groups, both after 48 h and 96 h of exposure. In Malpighian tubules, vacuolation is the only damage present. As the observed morphological alterations likely compromise the excretion and absorption functions, exposure to pyraclostrobin and thiamethoxam may lead to disturbances at both the individual and colony levels. These results highlight the urgent need for a future reassessment of the safety of fungicides and insecticides regarding their potential effects on bee populations.
(© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
Databáze: MEDLINE
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