A New Wolbachia-infection Model In A Two-sex Mosquito Population

In this paper,a new Wolbachia-infection model in a two-sex mosquito popula-tion is proposed.It incorporates some key effects of Wolbachia infection including incomplete cytoplasmic incompatibility(CI),male killing(MK)effect,maternal transmission,fertility cost of the Wolbachia infection to reproductive output,dif-ferent mortality rates for uninfected/infected male/female individuals and different sex-ratio effect for uninfected/infected females.Especially,the CI effect suffering by uninfected ova produced by infected females,which is often neglected,is con-sidered.We show that Wolbachia can be established in a mosquito population if the basic reproduction number,R0,is greater than one.When R0 is less than one,Wolbachia infection still can be established under some circumstances.The method to evaluate the threshold number of infected mosquitoes required to be released at the beginning is given.Sensitivity analysis and numerical simulation have been per-formed to study the impact of model parameters to Wolbachia establishment and population replacement.Our results show that low levels of MK effect and fitness costs as well as high levels of CI effect and maternal inheritance are in favor of Wolbachia establishment.Besides,it is worth emphasizing that without considering CI effect suffering by uninfected ova produced by infected females may result in the overestimation of the threshold infection level for Wolbachia invasion.