Abstract
MosChito raft, a Bacillus thuringiensis (Bti)-based formulation, represents a promising device for mosquito larvae control in domestic environments. Its chitosan matrix and active component, the commercial Bti product VectoBac 12AS, ensure high specificity and minimal environmental impact. This study evaluates the ecosafety of MosChito raft by assessing their effects on two aquatic model organisms, Daphnia magna and Danio rerio embryos. Both organisms were exposed to different MosChito rafts (Matrix, Yeast, Bti, Bti + Yeast). Embryos and larvae of D. rerio were monitored to assess acute toxicity, changes in swimming behavior, and alterations in key biochemical markers (ROS and AChE). Daphnids were exposed from hatching to 14 days, and the same markers as in D. rerio were evaluated, as well as their fertility. Across all tests, MosChito raft showed no acute toxicity. Behavioral assays in D. magna revealed a slight but statistically significant reduction in swimming activity after exposure to specific formulations. Biochemical analyses revealed mild oxidative stress in D. magna, although cholinergic signaling remained unaffected. No significant impact on D. magna fertility was found. Overall, our findings suggest that MosChito raft exerts negligible toxic effects on non-target aquatic species, supporting its use as an environmentally safe mosquito control tool, consistent with integrated pest management strategies aimed at minimizing ecological impact.
Data availability
Data will be made available on request from the corresponding author, S.E.
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Acknowledgements
We thank Cristina Lenardi (University of Milan, Department of Physics) for her constructive suggestions.
Funding
Funding was provided by the MUSA (Multilayered Urban Sustainability Action) project, funded by the European Union–NextGenerationEU under the National Recovery and Resilience Plan (NRRP) Mission 4 Component 2 Investment Line 1.5: Strengthening of research structures and creation of R&D “innovation ecosystems” and “territorial leaders in R&D”; PNRR project PE-13 INF-ACT “One Health Basic and Translational Research Actions addressing Unmet Needs on Emerging Infectious Diseases”.
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Negri Agata : Methodology, Investigation, Formal analysis, Writing—Original Draft, Project administration Nigro Lara : Methodology, Investigation, Software, Writing—Review & Editing Signorini Silvia Giorgia : Methodology, Investigation, Formal analysis Locarno Silvia : Methodology, Resources Diana Alberto : Methodology, Resources Caccia Silvia : Writing—Review & Editing, Validation Gabrieli Paolo : Data Curation, Validation, Writing—Review & Editing Binelli Andrea : Resurces, Validation, Visualization Del Giacco Luca : Resurces, Validation, Visualization Bandi Claudio : Supervision, Funding acquisition Della Torre Camilla : Supervision, Visualization, Investigation, Data Curation Epis Sara : Conceptualization, Supervision , Project administration.
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All experiments involving Danio rerio and Daphnia magna complied with Directive 2010/63/EU and applicable national regulations. Work on D. rerio was limited to embryos up to 120 hpf, which are not classified as protected animals under the Directive. D. magna is an invertebrate species and therefore falls outside the requirement for ethical approval.
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Negri, A., Nigro, L., Signorini, S.G. et al. Ecotoxicological and behavioural responses of aquatic model organisms to the MosChito raft bioinsecticide delivery system. Sci Rep (2026). https://doi.org/10.1038/s41598-026-39702-1
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DOI: https://doi.org/10.1038/s41598-026-39702-1