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Susceptibility and Emerging Resistance of Culex Mosquitoes to Lambda-Cyhalothrin and Dichlorvos in Minna, Niger State, Nigeria
Subject area: Biological & Medical Sciences · Area of research: Vector Biology and Medical Entomology
Abstract
The persistent challenge of controlling Culex mosquitoes, which are critical vectors for debilitating diseases such as lymphatic filariasis and various arboviruses, continues to hinge on the application of chemical insecticides. A formidable obstacle to these control efforts on a global scale is the escalating development of resistance to these chemicals within mosquito populations. This investigation was therefore designed to evaluate the current susceptibility profile of wild Culex mosquitoes sourced from Minna, Nigeria, when exposed to two widely utilized insecticides: lambda-cyhalothrin and dichlorvos. Field-collected immature stages from breeding sites in the Bosso Local Government Area were reared under controlled laboratory conditions to adulthood. Subsequent susceptibility testing was performed using the standard World Health Organization (WHO) tube bioassay protocol. Adult mosquitoes were exposed to filter papers treated with two distinct concentrations of each insecticide: a lower concentration (0.4% for lambda-cyhalothrin and 3.0% for dichlorvos) and a higher, diagnostic concentration (0.7% for lambda-cyhalothrin and 7.0% for dichlorvos). Knockdown was monitored at 10-minute intervals for one hour, with final mortality assessed after a 24-hour recovery period. The results revealed a stark, concentration-dependent response. The lower concentrations induced mortalities of only 52.63% ? 5.42 for lambda-cyhalothrin and 66.66% ? 3.83 for dichlorvos after one hour, figures that fall substantially below the WHO's 98% susceptibility benchmark, thereby confirming resistance. Conversely, the higher diagnostic doses achieved mortalities of 98.48% ? 1.51 and 98.67% ? 1.33, technically classifying the population as susceptible. However, the critical finding was that after 24 hours, mortality for the low concentrations remained incomplete at 87.54% and 84.06%, indicating a resilient sub-population. This study concludes that while the high diagnostic doses remain effective for now, the clear evidence of resistance at lower concentrations signals an urgent need for proactive insecticide resistance management strategies in the region to preserve the utility of these vital public health tools.
Keywords
Culex Mosquitoes, Insecticide Resistance, Lambda-Cyhalothrin, Dichlorvos, WHO Bioassay, Minna, Nigeria
References
[1] A. Farajollahi, D. M. Fonseca, L. D. Kramer, and A. M. Kilpatrick, "Bird biting mosquitoes and human disease: a review of the role of Culex pipiens complex mosquitoes in epidemiology," Infect. Genet. Evol., vol. 11, no. 7, pp. 1577–1585, 2011, doi: 10.1016/j.meegid.2011.06.009.
[2] M. Rodriquez, E. Ortiz, J. A. Bisset, and J. Hemingway, "Changes in malathion and pyrethroid resistance after cypermethrin selection of Culex quinquefasciatus field populations of Cuba," Med. Vet. Entomol., vol. 7, pp. 117–121, 1993, doi: 10.1111/j.1365-2915.1993.tb00665.x.
[3] World Health Organization, Global insecticide use for vector control: a 10-year assessment (2010-2019). Geneva: WHO, 2021.
[4] A. Rivero, J. Vézilier, M. Weill, A. F. Read, and S. Gandon, "Insecticide control of vector-borne diseases: when is insecticide resistance a problem?," PLoS Pathog., vol. 6, no. 8, p. e1001000, 2010, doi: 10.1371/journal.ppat.1001000.
[5] V. Corbel and R. N'Guessan, "Distribution, mechanisms, impact and management of insecticide resistance in malaria vectors: A pragmatic review," in Anopheles mosquitoes - New insights into malaria vectors, S. Manguin, Ed. IntechOpen, 2013. doi: 10.5772/56117.
[6] H. Ben Cheikh, Z. Ben Ali-Haouas, M. Marquine, and N. Pasteur, "Resistance to organophosphorus and pyrethroid insecticides in Culex pipiens (Diptera: Culicidae) from Tunisia," J. Med. Entomol., vol. 35, no. 3, pp. 251–260, 1998, doi: 10.1093/jmedent/35.3.251.
[7] M. A. Gorouhi, H. Vatandoost, M. A. Oshaghi, et al., "Current susceptibility status of Anopheles stephensi (Diptera: Culicidae) to different imagicides in a malarious area, South-eastern of Iran," J. Arthropod Borne Dis., vol. 10, no. 4, pp. 493–500, 2016.
[8] V. Corbel, R. N'Guessan, C. Brengues, et al., "Multiple insecticide resistance mechanisms in Anopheles gambiae and Culex quinquefasciatus from Benin, West Africa," Acta Trop., vol. 101, no. 3, pp. 207–216, 2007, doi: 10.1016/j.actatropica.2007.02.002.
[9] R. Feyereisen, "Insect P450 inhibitors and insecticides: challenges and opportunities," Pest Manag. Sci., vol. 71, no. 6, pp. 793–800, 2015, doi: 10.1002/ps.3895.
[10] J. Hemingway and H. Ranson, "Insecticide resistance in insect vectors of human disease," Annu. Rev. Entomol., vol. 45, pp. 371–391, 2000, doi: 10.1146/annurev.ento.45.1.371.
[11] M. C. Akogbéto, R. Djouaka, and H. Noukpo, "Use of agricultural insecticides in Benin," Bull. Soc. Pathol. Exot., vol. 98, no. 5, pp. 400–405, 2005.
[12] A. Diabate, T. Baldet, F. Chandre, et al., "The role of agricultural use of insecticides in resistance to pyrethroids in Anopheles gambiae s.l. in Burkina Faso," Am. J. Trop. Med. Hyg., vol. 67, no. 6, pp. 617–622, 2002, doi: 10.4269/ajtmh.2002.67.617.
[13] World Health Organization, Instructions for determining the susceptibility or resistance of mosquito larvae to insecticides, WHO/VBC/81.807. Geneva: WHO, 1981.
[14] R. M. Oxborough, A. Seyoum, Y. Yihdego, et al., "Susceptibility testing of Anopheles malaria vectors with the neonicotinoid insecticide clothianidin; results from 16 African countries," Malar. J., vol. 18, no. 1, pp. 1–11, 2019, doi: 10.1186/s12936-019-2885-9.
[15] World Health Organization, Test procedures for insecticide resistance monitoring in malaria vector mosquitoes, 2nd ed. Geneva: WHO, 2016.
[16] T. R. Fukuto, "Mechanism of action of organophosphorus and carbamate insecticides," Environ. Health Perspect., vol. 87, pp. 245–254, 1990, doi: 10.1289/ehp.9087245.
[17] T. E. Nkya, I. Akhouayri, W. Kisinza, and J. P. David, "Impact of environment on mosquito response to pyrethroid insecticides: Facts, evidences and prospects," Insect Biochem. Mol. Biol., vol. 43, no. 4, pp. 407–416, 2013, doi: 10.1016/j.ibmb.2012.10.006.
[18] A. Yadouléton, K. Badirou, R. Agbanrin, et al., "Insecticide resistance status in Culex quinquefasciatus in Benin," Parasites Vectors, vol. 8, p. 17, 2015, doi: 10.1186/s13071-015-0638-3.
[19] J. A. Scott, "The molecular genetics of resistance: resistance as a response to stress," Fla. Entomol., vol. 78, no. 3, pp. 399–414, 1995.
[20] K. Itokawa, O. Komagata, S. Kasai, Y. Okamura, M. Masada, and T. Tomita, "Genomic structures of Cyp9m10 in pyrethroid resistant and susceptible strains of Culex quinquefasciatus," Insect Biochem. Mol. Biol., vol. 40, no. 9, pp. 631–640, 2010, doi: 10.1016/j.ibmb.2010.06.001.
How to cite this paper
@article{1712227,
author = {Joshua Tsado Vatsa, Timileyin Joshua Oluwadepo, Godwin Kelechukwu Ezikanyi, Adeniyi Olusegun Oyeyemi, Hassan Abdulsalam Adewuyi},
title = {Susceptibility and Emerging Resistance of Culex Mosquitoes to Lambda-Cyhalothrin and Dichlorvos in Minna, Niger State, Nigeria},
journal = {Iconic Research And Engineering Journals},
year = {2025},
volume = {9},
number = {5},
pages = {1804-1809},
issn = {2456-8880},
url = {https://www.irejournals.com/formatedpaper/1712227.pdf},
abstract = {The persistent challenge of controlling Culex mosquitoes, which are critical vectors for debilitating diseases such as lymphatic filariasis and various arboviruses, continues to hinge on the application of chemical insecticides. A formidable obstacle to these control efforts on a global scale is the escalating development of resistance to these chemicals within mosquito populations. This investigation was therefore designed to evaluate the current susceptibility profile of wild Culex mosquitoes sourced from Minna, Nigeria, when exposed to two widely utilized insecticides: lambda-cyhalothrin and dichlorvos. Field-collected immature stages from breeding sites in the Bosso Local Government Area were reared under controlled laboratory conditions to adulthood. Subsequent susceptibility testing was performed using the standard World Health Organization (WHO) tube bioassay protocol. Adult mosquitoes were exposed to filter papers treated with two distinct concentrations of each insecticide: a lower concentration (0.4% for lambda-cyhalothrin and 3.0% for dichlorvos) and a higher, diagnostic concentration (0.7% for lambda-cyhalothrin and 7.0% for dichlorvos). Knockdown was monitored at 10-minute intervals for one hour, with final mortality assessed after a 24-hour recovery period. The results revealed a stark, concentration-dependent response. The lower concentrations induced mortalities of only 52.63% ? 5.42 for lambda-cyhalothrin and 66.66% ? 3.83 for dichlorvos after one hour, figures that fall substantially below the WHO's 98% susceptibility benchmark, thereby confirming resistance. Conversely, the higher diagnostic doses achieved mortalities of 98.48% ? 1.51 and 98.67% ? 1.33, technically classifying the population as susceptible. However, the critical finding was that after 24 hours, mortality for the low concentrations remained incomplete at 87.54% and 84.06%, indicating a resilient sub-population. This study concludes that while the high diagnostic doses remain effective for now, the clear evidence of resistance at lower concentrations signals an urgent need for proactive insecticide resistance management strategies in the region to preserve the utility of these vital public health tools.},
keywords = {Culex Mosquitoes, Insecticide Resistance, Lambda-Cyhalothrin, Dichlorvos, WHO Bioassay, Minna, Nigeria},
month = {November},
doi = {https://doi.org/10.64388/IREV9I5-1712227}
}