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Publication
Toxicity of the insecticides spinosad and indoxacarb to the non-target aquatic midge Chironomus riparius
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Advisor(s)
Abstract(s)
Spinosad and indoxacarb are two relatively new insecticides mainly used in agriculture to control insect pests.
However, at their current application rates, non-target aquatic insect species may also be impacted. In this
study, larvae of the non-biting midge Chironomus riparius were exposed in the laboratory to both insecticides
and their effects evaluated at the organismal level, using standard ecotoxicological tests, and at the biochemical
level, by monitoring specific oxidative stress, neuronal, and energy metabolism biomarkers. Chronic exposure to
both insecticides compromised growth and emergence of C. riparius. Short-term exposures revealed alterations
at biochemical level that might be related to the toxicological targets of both insecticides. Growth and development time were the most sensitive endpoints at individual level for both pesticides, while at the biochemical
level, the electron transport system activity was the most sensitive biomarker for spinosad exposure, suggesting
an increase in energy demands associated with the activation of defense mechanisms. Glutathione-S-transferase
was the most sensitive biomarker for indoxacarb exposure, underlining the role of this enzyme in the detoxification of indoxacarb. Additionally, changes in lactate dehydrogenase and glutathione peroxidase activities were observed for both insecticides, and evidences of oxidative damage were found for spinosad. This study contributes to the growing knowledge on sublethal effects of novel insecticides on non-target aquatic invertebrates and strengthens the usefulness of biochemical biomarkers to support the interpretation of their potentially deleterious effects on aquatic insects near agricultural fields.
Description
This study had the support of the Fundação para a Ciência e a
Tecnologia (FCT) through MARE: UID/MAR/04292/2019; CESAM: UID/
AMB/50017/2019, FCT/MCTES through national funds, the co-funding
by the FEDER within the PT2020 Partnership Agreement and Compete
2020; Project PROTEOME (PTDC/AAG-MAA/1302/2014) co-financed by
COMPETE (POCI-01-0145-FEDER-016773). The project was also partially
funded by the Integrated Programme of SR&TD “SmartBioR” (reference
Centro-01-0145-FEDER-000018) co-funded by Centro 2020 program,
Portugal2020, European Union, through the European Regional Development Fund. Hugo R. Monteiro, Sara C. Novais, and João L.T. Pestana wish to acknowledge the financial support given by FCT (SFRH/BD/80988/2011, SFRH/BPD/94500/2013, IF/01420/2015, respectively).
Keywords
Aquatic invertebrates Biochemical biomarkers Insecticides Life-history effects Neurotoxicity
Citation
Monteiro, H. R., Pestana, J. L. T., Soares, A. M. V. M., Novais, S. C., & Lemos, M. F. L. (2019). Toxicity of the insecticides spinosad and indoxacarb to the non-target aquatic midge Chironomus riparius. Science of the Total Environment, 666, 1283–1291. https://doi.org/10.1016/j.scitotenv.2019.02.303