A simple method for calculating mosquito mortality rates, correcting for seasonal variations in recruitment

A simple age-structured exponential growth model is presented for the analysis of the population dynamics of mosquitoes (Diptera: Culicidae). In this model, the proportion of parous mosquitoes R depends on the birth rate beta, and the length of the first gonotrophic cycle g, but not on the mortality rate. If the age structure is fairly constant, R = exp(- betag). Extensions of the model correcting for feeding patterns are given. A simple method is applied to an example of Anopheles gambiae Giles biting density and parity ratio in Cĵte d'Ivoire (fortnightly sampled longitudinal data set), for calculation of the seasonally fluctuating mortality rate, correcting for effects of recruitment. The seasonal variations in birth rate and mortality rate are discussed in relation to variations in density and rainfall.