Abstract
Understanding the nutritional physiology of mosquito larvae is crucial for optimizing mass-rearing practices and improving control strategies. Here we combined complementary optical and spectroscopic techniques, including fluorescence microscopy, confocal spectral imaging and Attenuated Total Reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy, to trace food ingestion in Aedes albopictus larvae. Differences in autofluorescence (AF) signal intensity and spatial distribution were observed in the gut of larvae reared in polystyrene (PS) or glass (GL) containers, suggesting that AF may serve as a relative proxy for evaluating ingestion efficiency. Chlorophyll-derived AF was detected outside the gut within the larval body, indicating systemic distribution of food-derived fluorophores. Spectral analysis of rearing water before and after larval development revealed changes in flavin-associated fluorescence profiles, consistent with flavin metabolism. Moreover, ATR-FTIR spectroscopy of larval gut samples revealed differences in chemical functional groups between larvae reared in PS or GL containers, suggesting ingestion of PS-derived material released from rearing containers. Despite the spectroscopic differences observed between rearing conditions, no clear effects were detected on standard mosquito life-history traits. Taken together, these findings highlight the potential of fluorescence- and ATR-FTIR-based techniques as sensitive tools to explore mosquito larval biology and nutrition. These approaches can reveal subtle yet biologically relevant effects of the rearing environment, a key factor in vector control programmes.
Data availability
Raw data corresponding to mosquito larval and pupal development duration, mortality and wing size, spectral data from confocal and spectrofluorimetric analyses, and individual ATR-FTIR spectra with the corresponding mean spectra used for second-derivative analysis are available at https://osf.io/z7gxh/?view_only=6679b05a9106405894e721e5cfc59889.
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Acknowledgements
The authors are grateful to Arianna Puggioli and Romeo Bellini (Centro Agricoltura Ambiente “G. Nicoli”, Crevalcore, Italy) for providing Ae. albopictus eggs. This study was performed within the Food and Agriculture Organization/International Atomic Energy Agency (FAO/IAEA) Coordinated Research Project “Reproductive biology of male Aedes mosquitoes for SIT applications” and benefited from discussions at IAEA funded meetings therein. The support from the Ministero dell’Università e della Ricerca (MUR) and the University of Pavia through the program “Dipartimenti di Eccellenza 2023–2027” is also acknowledged.
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S.S., M.L.W., A.O., A.G., A.M., and A.C.C. performed the experiments; S.S., M.L.W., A.C.C. M.L. and L.M.G. analyzed the data; F.S. conceived and designed the study, supervised the work and wrote the paper with contributions from all authors. All authors reviewed and approved the final version of the manuscript.
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Soldano, S., Weththimuni, M.L., Oldani, A. et al. Autofluorescence and Fourier transform infrared analyses trace dietary fluorophores and reveal plastic contamination in the gut of mosquito larvae. Sci Rep (2026). https://doi.org/10.1038/s41598-026-38938-1
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DOI: https://doi.org/10.1038/s41598-026-38938-1
