Background: Malaria vectors reproduce through in-flight copulation within swarms, which remains poorly understood. Gaining insights into swarming and mating behavior is essential for optimizing novel vector control strategies including sterile insect technique, genetically modified mosquitoes, and behavior based intervention. This study investigates the factors influencing swarm dynamics and mating efficiency in Anopheles coluzzii . Methods: We surveyed swarms across 40 residential compounds in Burkina Faso, georeferencing swarming sites and recording swarming times and height. In a subset of three compounds selected for detailed characterization, we also measured inter-swarm distances, counted swarm size from photography, and mating pairs through direct observation during swarming. Furthermore, we collected 30% of male mosquitoes from swarms to measure wing length and perform PCR analyses. We monitored environmental variables including temperature, humidity, wind speed, and luminosity. Finally, we performed spatial and statistical analysis using ArcGIS and R to determine how swarm and mating dynamics are correlated and how they depend on biological and environmental conditions. Results: We identified 169 Anopheles coluzzii swarms and found strong evidence of spatial clustering (General G: P < 0.001; Moran’s I = 0.2, P < 0.001), with localized hotspots. Swarming occurred between 18:05 h and 18:45 h, extending into darkness at ~19:15 h. Swarms had an average height of 2.87 m (range: 1.0–3.2 m) and consisted of 83–2783 mosquitoes. Swarm size strongly predicted pairing success in Anopheles coluzzii ( t = 9.16, P < 0.001) with larger swarms producing more pairs. However, individual pairing efficiency decreased with swarm size ( t = −3.515, P < 0.001). Male size positively influenced individual pairing efficiency ( t = 3.25, P = 0.002) but did not affect swarm size or total pairing frequency. Inter-swarm distances varied nonrandomly, suggesting interactions between neighboring and/or swarm markers. Conclusions: This study shows that An. coluzzii swarming is shaped by both biological and environmental factors. While larger males achieved higher individual mating efficiency, swarm size was the strongest predictor of mating success. Larger swarms yielded more mating pairs overall, although efficiency declined with increasing density. In addition, swarms formed in clustered nonrandom patterns within compounds. These results highlight the interplay between male traits and environment in shaping swarming dynamics. Graphical

Background: In aquatic larval habitats, Anopheles larvae are subject to the predatory activity and competition of macroinvertebrates. These macroinvertebrates may play a key role in the Anopheles population’s bioregulation in aquatic habitats and malaria control. There are few studies characterizing macroinvertebrate predators and other macroinvertebrates coexisting with Anopheles larvae in Burkina Faso. This study aimed at characterizing and evaluating the different interactions between anopheline mosquito larvae, predatory macroinvertebrates, and other co-habitants in aquatic habitats in the three climatic zones of Burkina Faso. Methods: A larval survey was performed in the three climatic zones of Burkina Faso (Sahelian, Soudano-Sahelian, and Soudanian zones) from September to November 2022. Mosquito larvae and other macroinvertebrates were sampled using standard dippers or bucket, preserved in Falcon tubes containing 80% ethanol, and transported to the laboratory for morphological identification. Alpha diversity analysis was used to measure macroinvertebrate diversity according to climatic zones and correlation matrix analysis was performed to determine the different interactions between Anopheles and other macroinvertebrates in breeding sites. Results: In the studied larval habitats, Anopheles were found with several aquatic macroinvertebrate predators and other cohabiting macroinvertebrates. The abundance and alpha diversity indices of macroinvertebrate predators and other coexisting macroinvertebrates varied significantly according to climatic zone (P = 0.01). Correlation analyses showed that in the Sahelian zone, Anopheles spp., Corixidae, and Notonectidae shared the same aquatic habitats. In the Soudano-Sahelian zone, Anopheles spp. occupied the same larval habitats with Belostomatidae, Notonectidae, and Achatinidae, and in the Soudanian zone, their presence in larval habitats was correlated with that of Beatidae. Conclusions: This study showed a significant trophic association between Anopheles and predatory and other coexisting macroinvertebrates in larval habitats in Burkina Faso. Our study provides insights and thereby opens new avenues in terms of development of biological control against larvae of Anopheles populations in Burkina Faso. Graphical

Background: In aquatic larval habitats, Anopheles larvae are subject to the predatory activity of macroinvertebrates. These macroinvertebrates may play a key role in the Anopheles populations bioregulation in aquatic habitats and malaria control. There are few studies characterising macroinvertebrate predators and other macroinvertebrates coexisting with Anopheles larvae in Burkina Faso. This study aimed at characterising and evaluating the different interactions in larval habitats between anopheline mosquito larvae, predatory macroinvertebrates and other co-habitants in the three climatic areas of Burkina Faso. Methods: A larval survey was performed in the three climatic areas (Sahelian, Soudano-Sahelian and Soudanian zones) from September to November 2022. Mosquito larvae and other macroinvertebrates were sampled using standard dippers, preserved in Falcon tubes containing ethanol 80% and transported to the laboratory for morphological identification. Alpha diversity analysis was used to measure macroinvertebrate diversity according to climatic zones and correlation matrix analysis was performed to determine the different interactions between Anopheles and other macroinvertebrates in breeding sites. Results: As results, in larval habitats, Anopheles were found with several aquatic macroinvertebrate predators and other macroinvertebrates cohabiting with Anopheles. The abundance and alpha diversity indices of macroinvertebrate predators and other coexisting macroinvertebrates varied significantly according to climatic zone. Correlation analyses showed that in the Sahelian zone, Anopheles spp., Corixidae and Notonectidae shared the same aquatic habitats. In the Soudano-Sahelian zone, Anopheles spp. occupied the same larval habitats with Belostomatidae, Notonectidae and Achatinidae and the presence of Anopheles in larval habitats was correlated with that of Beatidae in the Soudanian zone. Conclusion: This study showed a trophic association between Anopheles, macroinvertebrate predators and other coexisting macroinvertebrates in larval habitats in Burkina. Our study provides insights and thereby opens new avenues in terms of development of biological control against larvae of Anophelespopulations in Burkina Faso.