Ecological analysis of mosquito larval communities in Burkina Faso to inform environmental monitoring of genetic control programs

Abstract

In Burkina Faso, the development of the gene drive technology targeting Anopheles coluzzii raises important ecological questions about potential non-target effects. Understanding interactions in mosquitoes’ natural environments is crucial for developing effective post-release environmental safety monitoring. This study assesses the ecological exposure and potential risks to non-target organisms associated with An. coluzzii suppression. Using co-occurrence, niche overlap metrics, and characterisation of physicochemical parameters, we evaluated interspecific relationships among mosquitoes and macroinvertebrate taxa from larval habitats in Burkina Faso. Combined index revealed distinct ecological relationships, ranging from competitive or facilitative coexistence to spatial segregation driven by predation or behavioural avoidance. Based on these interactions, an exposure score was developed to quantify the potential susceptibility of non-target organisms to ecological changes following the removal of An. coluzzii. The results showed variable exposure among taxa, with An. gambiae s.s. having the highest score, followed by An. arabiensis and Culex spp. Predatory taxa such as Corixidae showed niche overlap but limited spatial co-occurrence, suggesting effective predation. The detection of hybrid forms (An. coluzzii x An. gambiae s.s.) further highlights the potential for gene flow. This study introduces a quantitative framework that combines ecological indices and exposure scores to predict potential risks to non-target organisms.