A stage structured model for mosquito suppression with immigration.

Area of Science:

• Vector control
• Mathematical biology
• Epidemiology

Background:

• Mosquito-borne diseases like dengue, malaria, and Zika pose significant global health threats.
• The incompatible insect technique (IIT) using Wolbachia offers a novel biological control strategy.
• Maintaining control program efficacy against immigrating fertile mosquitoes is crucial for success.

Purpose of the Study:

• To model the dynamics of Wolbachia-based mosquito control considering larval and adult stages.
• To analyze the impact of releasing Wolbachia-infected males and immigrating fertile females on population suppression.
• To determine critical thresholds for immigration to ensure effective control.

Main Methods:

• Formulation of a system of delay differential equations to simulate mosquito population dynamics.
• Analysis of system stability (globally asymptotically stable or bistable) based on release and immigration parameters.
• Identification of the maximum permissible immigration number of fertile females for targeted population reduction.

Main Results:

• Immigration of fertile females significantly reduces the maximum achievable suppression efficiency.
• A critical immigration threshold was identified below which effective population reduction is possible.
• Reducing wild female immigration to less than 0.21% of adult carrying capacity is necessary for 90% reduction within two months.

Conclusions:

• Wolbachia-based IIT requires careful management of immigrating fertile females for optimal results.
• Mathematical modeling provides essential insights into designing effective vector control strategies.
• Controlling immigration is a vital component for the long-term success of Wolbachia mosquito control programs.