Optimizing integrated mosquito control with SIT and natural enemies

The sterile insect technique (SIT) is an eco-friendly insect management tool that aims to suppress or eliminate wild insect populations by releasing sterile individuals. In this study, we formulate a mathematical model that integrates SIT with the continuous release of natural predators to suppress wild mosquito populations. We consider two release strategies for sterile mosquitoes: constant release (CR) and saturating proportional release (SPR). Our analysis reveals that successful wild mosquito eradication depends on initial population densities and critical release thresholds, which vary in relation to predator efficacy, mosquito life-history traits and sterile mosquito fitness. While SIT alone can suppress mosquito populations, its combination with predator release significantly enhances control efficacy. Although the CR strategy proves more effective than SPR in achieving eradication, optimal control analysis reveals that SPR outperforms CR in population suppression, especially when the costs of sterile mosquito release increase. Additionally, increased social investment in mosquito control efforts enhances suppression outcomes under both release strategies, suggesting a feedback mechanism in which increased societal urgency leads to more robust and effective vector control efforts.