Abstract
Most malaria vector control strategies target female Anopheles mosquitoes that transmit parasites, but emerging approaches such as gene drive, sterile insect technique, or Wolbachia require the release of males. Successful deployment depends on reliable knowledge of the species composition and age structure of male populations to overcome potential barriers to mating. Although approaches including near-infrared spectroscopy have been explored for male species identification and age grading, these methods remain constrained by limited validation, scalability, and accuracy under operational field conditions. Here we tested mid-infrared spectroscopy (MIRS) coupled with machine learning (ML) as a rapid and cost-effective approach for classifying species and age of male mosquitoes within the Anopheles gambiae complex. We used male mosquitoes from two laboratory-reared colonies in Burkina Faso (Anopheles coluzzii and An. gambiae) to develop a MIRS-ML model for species and age group (1–4, 5–10, 11–17 days) prediction under controlled conditions. This model was tested against a genetic and environmentally variable dataset consisting of male offspring obtained from gravid or blood fed Anopheles coluzzii and An. gambiae females collected from houses from two villages, Vallée du Kou and Soumousso and reared to adulthood in a semi-field system. The MIRS spectra from 2,120 males, representing both species, all age groups and both laboratory and semi-field backgrounds, were analysed using an extreme gradient boosting (XGBoost) algorithm to assess the ability to correctly predict age group and species. The XGBoost model classified mosquito species (86%) and age groups (85%) accurately in laboratory data, but performance declined under semi-field conditions (64% for species, 50% for age), reflecting environmental variability. Incorporating semi-field samples through transfer learning improved accuracy to 73% for species and 70% for age, underscoring both the limits of laboratory-only models and the value of transfer learning for enhancing generalisability in field settings. Our results demonstrate that mid-infrared spectroscopy with supervised machine learning (MIRS-ML) holds potential as a rapid tool for identifying the species and age group of cryptic male malaria vectors and represent one of the first applications of this approach to male Anopheles gambiae s.l. evaluated under semi-field conditions. However, before the approach can be used, larger datasets are needed to improve the classification algorithms and validate them for prediction in field populations.
Data availability
Software name: Python 3.12 , OPUS: [https://github.com/magonji/opus-dei](https:/github.com/magonji/opus-dei), Codes and data can be accessed at: [https://github.com/MwangaEP/Male-age-species](https:/github.com/MwangaEP/Male-age-species).
References
Ferguson, H. M., John, B., Ng’habi, K. & Knols, B. G. J. Redressing the sex imbalance in knowledge of vector biology. Trends Ecol. Evol. 20 (4), 202–209. https://doi.org/10.1016/j.tree.2005.02.003 (2005).
Baldini, F. et al. The Interaction between a Sexually Transferred Steroid Hormone and a Female Protein Regulates Oogenesis in the Malaria Mosquito Anopheles gambiae. Schneider DS, editor. PLoS Biol. 11(10):e1001695. (2013). https://doi.org/10.1371/journal.pbio.1001695
Robinson, R. & His Hormone Her Oogenesis: How Male Malaria Mosquitoes Trigger Female Egg Development. PLoS Biol. 11 (10), e1001694. https://doi.org/10.1371/journal.pbio.1001694 (2013).
Fereda, D. E. Mating Behavior and Gonotrophic Cycle in Anopheles gambiae Complex and their Significance in Vector Competence and Malaria Vector Control. J. Biomed. Res. Environ. Sci. 3 (1), 031–43. https://doi.org/10.37871/jbres1398 (2022).
Diabate, A. & Tripet, F. Targeting male mosquito mating behaviour for malaria control. Parasit. Vectors. 8 (1), 347. https://doi.org/10.1186/s13071-015-0961-8 (2015).
Rakotonirina, A., Maquart, P. O., Flamand, C., Sokha, C. & Boyer, S. Mosquito diversity (Diptera: Culicidae) and medical importance in four Cambodian forests. Parasit. Vectors. 16 (1), 110. https://doi.org/10.1186/s13071-023-05729-w (2023).
Suh, P. F. et al. Impact of insecticide resistance on malaria vector competence: a literature review. Malar. J. 22 (1), 19. https://doi.org/10.1186/s12936-023-04444-2 (2023).
World Malaria report C. World malaria report 2023. https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2023
Dev, V., Wangdi, K. & Editorial World Malaria Day 2023 – ending malaria transmission: reaching the last mile to zero malaria. Front. Public. Health. 12, 1433213. https://doi.org/10.3389/fpubh.2024.1433213 (2024).
Yao, F. A. et al. Mark-release-recapture experiment in Burkina Faso demonstrates reduced fitness and dispersal of genetically-modified sterile malaria mosquitoes. Nat. Commun. 13 (1), 796. https://doi.org/10.1038/s41467-022-28419-0 (2022).
Alphey, L. Genetic Control of Mosquitoes. Annu. Rev. Entomol. 59 (1), 205–224. https://doi.org/10.1146/annurev-ento-011613-162002 (2014).
Gato, R. et al. Sterile Insect Technique: Successful Suppression of an Aedes aegypti Field Population in Cuba. Insects 12 (5), 469. https://doi.org/10.3390/insects12050469 (2021).
Krafsur, E. S., Whitten, C. J. & Novy, J. E. Screwworm eradication in North and Central America. Parasitol. Today. 3 (5), 131–137. https://doi.org/10.1016/0169-4758(87)90196-7 (1987).
Minwuyelet, A. et al. Symbiotic Wolbachia in mosquitoes and its role in reducing the transmission of mosquito-borne diseases: updates and prospects. Front. Microbiol. 14, 1267832. https://doi.org/10.3389/fmicb.2023.1267832 (2023). PubMed PMID: 37901801; PubMed Central PMCID: PMC10612335.
Moretti, R. et al. Exploiting Wolbachia as a Tool for Mosquito-Borne Disease Control: Pursuing Efficacy, Safety, and Sustainability. Pathogens 14 (3), 285. https://doi.org/10.3390/pathogens14030285 (2025).
Bhattacharyya, J. & Roelke, D. L. Wolbachia-based mosquito control: Environmental perspectives on population suppression and replacement strategies. Acta Trop. 262, 107517. https://doi.org/10.1016/j.actatropica.2024.107517 (2025).
Utarini, A. et al. Efficacy of Wolbachia-Infected Mosquito Deployments for the Control of Dengue. N Engl. J. Med. 384 (23), 2177–2186. https://doi.org/10.1056/NEJMoa2030243 (2021).
Indriani, C. et al. Reduced dengue incidence following deployments of Wolbachia-infected Aedes aegypti in Yogyakarta, Indonesia: a quasi-experimental trial using controlled interrupted time series analysis. Gates Open. Res. 4, 50. https://doi.org/10.12688/gatesopenres.13122.1 (2020).
Niang, A. et al. Entomological baseline data collection and power analyses in preparation of a mosquito swarm-killing intervention in south-western Burkina Faso. Malar. J. 20 (1), 346. https://doi.org/10.1186/s12936-021-03877-x (2021).
Sawadogo, S. P. et al. Comparison of entomological impacts of two methods of intervention designed to control Anopheles gambiae s.l. via swarm killing in Western Burkina Faso. Sci. Rep. 12 (1), 12397. https://doi.org/10.1038/s41598-022-16649-7 (2022).
Wagner, I. et al. Rapid identification of mosquito species and age by mass spectrometric analysis. BMC Biol. 21 (1), 10. https://doi.org/10.1186/s12915-022-01508-8 (2023).
Detinova, T. S. & Gillies, M. T. Observations on the Determination of the Age Composition and Epidemiological Importance of Populations of Anopheles gambiae Giles and Anopheles funestus Giles in Tanganyika. Bull World Health Organ.30(1):23–8. PMCID: PMC2554915 (1964).
Hugo, L. E., Quick-Miles, S., Kay, B. H. & Ryan, P. A. Evaluations of Mosquito Age Grading Techniques Based on Morphological Changes, Journal of Medical Entomology, Volume 45, Issue 3, 1 May 2008, Pages 353–369. https://doi.org/10.1093/jmedent/45.3.353
Charlwood, J. D., Pinto, J., Sousa, C. A., Ferreira, C. & Do Rosário, V. E. Male size does not affect mating success (of Anopheles gambiae in São Tomé). Med. Vet. Entomol. 16 (1), 109–111. https://doi.org/10.1046/j.0269-283x (2002). .2002.00342.x PubMed PMID: 11963975.
Oliva, C. F., Benedict, M. Q., Lempérière, G. & Gilles, J. Laboratory selection for an accelerated mosquito sexual development rate. Malar. J. 10 (1), 135. https://doi.org/10.1186/1475-2875-10-135 (2011).
Huho, B. J. et al. A reliable morphological method to assess the age of male Anopheles gambiae. Malar. J. 5 (1), 62. https://doi.org/10.1186/1475-2875-5-62 (2006).
Montalvo-Sabino, E. et al. Morphological and Molecular Characterization Using Genitalia and CoxI Barcode Sequence Analysis of Afrotropical Mosquitoes with Arbovirus Vector Potential. Diversity 14 (11), 940. https://doi.org/10.3390/d14110940 (2022).
Yaméogo, K. B. et al. Case Study for Undetermined Mosquito Species by Polymerase Chain Reaction in Western Burkina Faso. Am. J. Mol. Biol. 14 (02), 43–53. https://doi.org/10.4236/ajmb.2024.142004 (2024).
Chabanol, E. et al. A novel mosquito species identification method based on PCR and capillary electrophoresis. Preprints; 2023. Available from: https://www.authorea.com/users/597968/articles/630767-a-novel-mosquito-species-identification-method-based-on-pcr-and-capillary-electrophoresis?commit=919a398c3314025b0bcb73872ba2d9db70bfa186 doi:10.22541/au.167937904.48976746/v1.
Reichl, J. et al. Comparison of a multiplex PCR with DNA barcoding for identification of container breeding mosquito species. Parasit. Vectors. 17 (1), 171. https://doi.org/10.1186/s13071-024-06255-z (2024).
Mayagaya, V. S. et al. Non-destructive Determination of Age and Species of Anopheles gambiae s.l. Using Near-infrared Spectroscopy. Am. J. Trop. Med. Hyg. 81 (4), 622–630. https://doi.org/10.4269/ajtmh.2009.09-0192 (2009).
Sikulu-Lord, M. T. et al. Near-Infrared Spectroscopy, a Rapid Method for Predicting the Age of Male and Female Wild-Type and Wolbachia Infected Aedes aegypti. Barrera R, editor. PLoS Negl Trop Dis.10(10):e0005040. (2016). https://doi.org/10.1371/journal.pntd.0005040
Siria, D. J. et al. Rapid age-grading and species identification of natural mosquitoes for malaria surveillance. Nat. Commun. 13 (1), 1501. https://doi.org/10.1038/s41467-022-28980-8 (2022).
Caputo, B. et al. Identification and composition of cuticular hydrocarbons of the major Afrotropical malaria vector Anopheles gambiae s.s. (Diptera: Culicidae): analysis of sexual dimorphism and age-related changes. J. Mass. Spectrom. 40 (12), 1595–1604. https://doi.org/10.1002/jms.961 (2005).
Suarez, E. et al. Matrix-assisted laser desorption/ionization-mass spectrometry of cuticular lipid profiles can differentiate sex, age, and mating status of Anopheles gambiae mosquitoes. Anal. Chim. Acta. 706 (1), 157–163. https://doi.org/10.1016/j.aca.2011.08.033 (2011).
González Jiménez, M. et al. Prediction of mosquito species and population age structure using mid-infrared spectroscopy and supervised machine learning. Wellcome Open. Res. 4, 76. https://doi.org/10.12688/wellcomeopenres.15201.3 (2019). PubMed PMID: 31544155; PubMed Central PMCID: PMC6753605.
Foti, M. et al. Towards scalable age-grading of Aedes albopictus mosquito using mid-infrared spectroscopy and machine learning. Sci. Rep. 15 (1), 40470. https://doi.org/10.1038/s41598-025-24404-x (2025).
Namountougou, M. et al. Multiple Insecticide Resistance in Anopheles gambiae s.l. Populations from Burkina Faso, West Africa. PLoS ONE. 7 (11), e48412. https://doi.org/10.1371/journal.pone.0048412 (2012). PubMed PMID: 23189131; PubMed Central PMCID: PMC3506617.
Niang, A. et al. Semi-field and indoor setups to study malaria mosquito swarming behavior. Parasit. Vectors. 12 (1), 446. https://doi.org/10.1186/s13071-019-3688-0 (2019).
Santolamazza et al. Insertion polymorphisms of SINE200 retrotransposons within speciation islands of Anopheles gambiae molecular forms | Malaria Journal | Full Text. Available from: https://malariajournal.biomedcentral.com/articles/ (2008). https://doi.org/10.1186/1475-2875-7-163
Mwanga, E. P. et al. Using mid-infrared spectroscopy and supervised machine-learning to identify vertebrate blood meals in the malaria vector, Anopheles arabiensis. Malar. J. 18 (1), 187. https://doi.org/10.1186/s12936-019-2822-y (2019).
Mwanga, E. P. et al. Reagent-free detection of Plasmodium falciparum malaria infections in field-collected mosquitoes using mid-infrared spectroscopy and machine learning. Sci. Rep. 14 (1), 12100. https://doi.org/10.1038/s41598-024-63082-z (2024).
Mwanga, E. P. et al. Rapid classification of epidemiologically relevant age categories of the malaria vector, Anopheles funestus. Parasit. Vectors. 17 (1), 143. https://doi.org/10.1186/s13071-024-06209-5 (2024).
Mwanga, E. P. et al. Using transfer learning and dimensionality reduction techniques to improve generalisability of machine-learning predictions of mosquito ages from mid-infrared spectra. BMC Bioinform. 24 (1), 11. https://doi.org/10.1186/s12859-022-05128-5 (2023). PubMed PMID: 36624386; PubMed Central PMCID: PMC9830685.
da Silva, H. B., Barbosa, R. C., Rezende, P. H., Ayala-Costa, D. & Lino-Neto, J. New findings on the male reproductive system and spermatozoa of Aedes aegypti (Diptera: Culicidae). Parasit. Vectors. 18 (1), 246. https://doi.org/10.1186/s13071-025-06808-w (2025).
Degner, E. C. et al. Proteins, Transcripts, and Genetic Architecture of Seminal Fluid and Sperm in the Mosquito Aedes aegypti. Mol. Cell. Proteom. MCP. 18 (Suppl 1), S6–22. https://doi.org/10.1074/mcp.RA118.001067 (2019). PubMed PMID: 30552291; PubMed Central PMCID: PMC6427228.
Acknowledgements
We are grateful to Medical Research Council GCRF Infections Foundation Awards to A.D., F.B., F.O.O., H.M.F. and K.W, whose previous work on female mosquitoes inspired us to study male mosquitoes using MIRS. Authors thank the villagers who accepted to conduct the mosquito collection in their houses.
Funding
The current study is supported by ANTI-VeC grant (AV/TCA/002) to Roger Sanou, Abdoulaye Diabté at Institut de Recherche en Sciences de la Santé / Centre Muraz and Simon A. Babayan at University of Glasgow.
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Conceptualization: R.S., F.B., H.M.F., F.O.O., S.A.B.,D.J.S., A.M.G.B., R.K.D., K.W., M.G.J. and A.D. R.S., F.B., H.M.F., E.P.M, H.M. and M.G.J. wrote the main manuscript. Data analysis: E.P.M., B.B.S. and M.G.J. Mosquito collection and MIRS-spectra measurements: F.W. All authors reviewed the manuscript.
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Sanou, R., Mwanga, E.P., Sow, B.B.D. et al. Age-grading and species identification of male mosquito Anopheles gambiae s.l. using mid-infrared spectroscopy and machine learning.
Sci Rep (2026). https://doi.org/10.1038/s41598-026-46306-2
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DOI: https://doi.org/10.1038/s41598-026-46306-2
Keywords
Anopheles gambiae s.l.- Species
- Age
- Identification
- Malaria
- Mid-infrared spectroscopy
- Machine learning
Source: Ecology - nature.com
