Characterization of the swarming behavior of Anopheles coluzzii and Anopheles gambiae (Diptera: Culicidae) populations in a hybrid zone of Senegal.

Gueye, Oumou Kalsom; Niang, Abdoulaye; Faye, Mouhamed Bassir; Dia, Abdoulaye Kane; Ahmed, Amblat Ali; Sy, Ousmane; Tripet, Frederic; Konaté, Lassana; Dia, Ibrahima; Wondji, Charles Sinclair; Gaye, Oumar; Faye, Ousmane; Diabate, Abdoulaye; Niang, El Hadji Amadou

Abstract

Anopheles gambiae and Anopheles coluzzii, often found in sympatry and synchronous, have undergone a premating reproductive isolation across their distribution range. However, in the Western coast of Africa, unexpected hybridization zones have been observed, and little is known about swarming behavior of these cryptic taxa. Here, we characterized the swarming behavior of An. coluzzii and An. gambiae to investigate its role in the high hybridization level in Senegal. The study was conducted in the south and central Senegal during the 2018 rainy season. Mating swarms of malaria vectors were surveyed at sunset and collected using an insect net. Meanwhile, indoor resting populations of malaria vectors were collected by pyrethrum spray catches. Upon collection, specimens were identified morphologically, and then members of the An. gambiae complex were identified at the species level by polymerase chain reaction (PCR). An. gambiae swarmed mainly over bare ground, whereas An. coluzzii were found swarming above various objects creating a dark-light contrast with the bare ground. The swarms height varied from 0.5 to 2.5 m. Swarming starting time was correlated with sunset whatever the months for both species, and generally lasted about 10 min. No mixed swarm of An. gambiae and An. coluzzii was found even in the high hybridization area. These results indicated a premating isolation between An. coluzzii and An. gambiae. However, the high hybridization rate in the sympatric area suggests that heterogamous mating is occurring, thus stressing the need for further extensive studies. [Abstract copyright: © The Author(s) 2023. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: [e-mail].]

Citation

Gueye, O. K., Niang, A., Faye, M. B., Dia, A. K., Ahmed, A. A., Sy, O., …Niang, E. H. A. (in press). Characterization of the swarming behavior of Anopheles coluzzii and Anopheles gambiae (Diptera: Culicidae) populations in a hybrid zone of Senegal. Journal of Medical Entomology, 60(6), 1278–1287. https://doi.org/10.1093/jme/tjad120

• Journal Article Type: Article
• Acceptance Date: Aug 19, 2023
• Online Publication Date: Sep 20, 2023
• Deposit Date: Oct 9, 2023
• Journal: Journal of medical entomology
• Print ISSN: 0022-2585
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 60
• Issue: 6
• Article Number: tjad120
• Pages: 1278–1287
• DOI: https://doi.org/10.1093/jme/tjad120
• Keywords: Anopheles gambiae, Anopheles coluzzii, Senegal, hybridization, swarming behavior