Common predators and factors influencing their abundance in Anopheles funestus aquatic habitats in rural south-eastern Tanzania

Mahenge, H. H., Muyaga, L. L., Nkya, J. D., Kifungo, K. S., Kahamba, N. F., Ngowo, H. S. and Kaindoa, E. W. (2023) Common predators and factors influencing their abundance in Anopheles funestus aquatic habitats in rural south-eastern Tanzania. PLoS ONE, 18(6), e0287655. (doi: 10.1371/journal.pone.0287655) (PMID:37363899) (PMCID:PMC10292713)

Abstract

Background: The role of larval predators in regulating the Anopheles funestus population in various malaria-endemic countries remains relatively unknown. This study aimed to investigate the common predators that co-exist with Anopheles funestus group larvae and evaluate factors that influence their abundance in rural south-eastern Tanzania. Methods: Mosquito larvae and predators were sampled concurrently using standard dipper (350 ml) or 10 L bucket in previously identified aquatic habitats in selected villages in southern Tanzania. Predators and mosquito larvae were identified using standard identification keys. All positive habitats were geo-located and their physical features characterized. Water physicochemical parameters such as dissolved oxygen (DO), pH, electrical conductivity (EC), total dissolved solids (TDS) and temperature were also recorded. Results: A total of 85 previously identified An. funestus aquatic habitats in nine villages were sampled for larvae and potential predators. A total of 8,295 predators were sampled. Of these Coenagrionidae 57.7% (n = 4785), Corixidae 12.8% (n = 1,060), Notonectidae 9.9% (n = 822), Aeshnidae 4.9% (n = 405), Amphibian 4.5% (n = 370), Dytiscidae 3.8% (n = 313) were common. A total of 5,260 mosquito larvae were sampled, whereby Anopheles funestus group were 60.3% (n = 3,170), Culex spp. 24.3% (n = 1,279), An. gambie s.l. 8.3% (n = 438) and other anophelines 7.1% (n = 373). Permanent and aquatic habitats larger than 100m2 were positively associated with An. funestus group larvae (P<0.05) and predator abundance (P<0.05). Habitats with submerged vegetation were negatively associated with An. funestus group larvae (P<0.05). Only dissolved oxygen (DO) was positively and significantly affect the abundance of An. funestus group larvae (P<0.05). While predators’ abundance was not impacted by all physicochemical parameters. Conclusion: Six potential predator families were common in aquatic habitats of An. funestus group larvae. Additional studies are needed to demonstrate the efficacy of different predators on larval density and adult fitness traits. Interventions leveraging the interaction between mosquitoes and predators can be established to disrupt the transmission potential and survival of the An. funestus mosquitoes.

• Item Type: Articles
• Additional Information: The study was financially supported by the Ifakara Health Institute Training Unit awarded to HHM together with Consortium for Advanced Research Training in Africa (CARTA) awarded to EWK. CARTA is jointly led by the African by the Carnegie Corporation of New York (Grant No. G-19-57145), Sida (Grant No:54100113), Uppsala Monitoring Center, Norwegian Agency for Development Cooperation (Norad), and by the Wellcome Trust [reference no. 107768/Z/15/Z] and the UK Foreign, Commonwealth & Development Office, with support from the Developing Excellence in Leadership, Training and Science in Africa (DELTAS Africa) programme. EWK was also funded by National Institute for Health Research: NIHR–Wellcome Trust Partnership for Global Health Research International Training Fellowship (Grant Number: 216448/Z/19/Z).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Ngowo, Halfan

Creator Roles

Ngowo, H. S.: Conceptualization, Formal analysis, Methodology, Supervision, Writing – review and editing

• Authors: Mahenge, H. H., Muyaga, L. L., Nkya, J. D., Kifungo, K. S., Kahamba, N. F., Ngowo, H. S., and Kaindoa, E. W.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: PLoS ONE
• Publisher: Public Library of Science
• ISSN: 1932-6203
• ISSN (Online): 1932-6203
• Copyright Holders: Copyright © 2023 Mahenge et al.
• First Published: First published in PLoS ONE 18(6): e0287655
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10.5061/dryad.kwh70rz7z