Baafi, J. | bioRxiv Science

bioRxiv2025

Effect of Climate Warming on Mosquito Population Dynamics in Newfoundland

Mosquitoes are key vectors of several infectious diseases affecting humans and animals. In North America, Culex mosquitoes are primary vectors of West Nile virus, St. Louis encephalitis, and Japanese encephalitis, as well as pathogens that impact birds and horses. The Culex life cycle consists of four stages, eggs, larvae, pupae, and adults, each with distinct development and mortality rates. Only active (non-diapausing) adults can reproduce, and environmental factors such as temperature, photoperiod, and rainfall influence population dynamics and stage-specific abundances. We develop a stage-structured model that integrates historical climate data and available experimental data to describe how key climate variables regulate life history parameters. Specifically, oviposition rates depend on temperature, maturation and survival are influenced by both temperature and rainfall, mortality is modeled as temperature-dependent, and diapause induction and termination are driven by photoperiod. Unlike many previous models focused on tropical mosquitoes, our framework explicitly incorporates diapause, a critical adaptation for temperate Culex populations. Simulations reveal strong nonlinear responses to warming, moderate temperature shifts amplify the differences in mosquito abundance across rainfall regimes, whereas higher warming leads to convergence at consistently high densities. Rainfall amounts determine whether populations remain suppressed, variable, or strongly amplified, whereas warming extends the active season and elevates population abundance. These results underscore the importance of jointly considering temperature, rainfall, and photoperiod in predicting mosquito dynamics. Our findings suggest that climate change may expand the seasonal window of mosquito activity and raise vector abundance, thereby increasing opportunities for pathogen transmission. The model provides a mechanistic framework for exploring how interacting climate drivers shape vector ecology and highlights priorities for data collection and adaptive control strategies under environmental change.

ecology↗

bioRxiv2024

Modeling the Impact of Seasonality on Mosquito Population Dynamics: Insights for Vector Control Strategies.

Mosquitoes are important vectors for the transmission of some major infectious diseases of humans, i.e., malaria, dengue, West Nile Virus and Zika virus. The burden of these diseases is different for different regions, being highest in tropical and subtropical areas, which have high annual rainfall, warm temperatures, and less pronounced seasonality. The life cycle of mosquitoes consists of four distinct stages: eggs, larvae, pupae, and adults. These life stages have different mortality rates and only adults can reproduce. Seasonal weather may affect the population dynamics of mosquitoes, and the relative abundance of different mosquito stages. We developed a stage-structured model that considers laboratory experiments describing how temperature and rainfall affects the reproduction, maturation and survival of different Anopheles mosquito stages, the species that transmits the parasite that causes malaria. We consider seasonal temperature and rainfall patterns and describe the stage-structured population dynamics of the Anopheles mosquito in Ain Mahbel, Algeria, Cape Town, South Africa, Nairobi, Kenya and Kumasi, Ghana. We find that neglecting seasonality leads to significant overestimation or underestimation of mosquito abundance. We find that depending on the region, mosquito abundance: peaks one, two or four times a year, periods of low abundance are predicted to occur for durations ranging from six months (Ain Mahbel) to not at all (Nairobi); and seasonal patterns of relative abundance of stages are sub-stantially different. The region with warmer temperatures and higher rainfall across the year, Kumasi, Ghana, is predicted to have higher mosquito abundance, which is broadly consistent with reported malaria deaths relative to the other countries considered by our study. Our analysis reveals distinct patterns in mosquito abundance across different months and regions. Control strategies often target one specific life stage, for example, applying larvicides to kill mosquito larvae, or spraying insecticides to kill adult mosquitoes. Our findings suggest that differences in seasonal weather affect mosquito stage structure, and that the best approaches to vector control may differ between regions in timing, duration, and efficacy.

ecology↗