Mathematical model of the survival rates of female bushflies (Musca vetustissima Walker) (Diptera: Muscidae) as inferred from field populations

Abstract

The survival rate of the females of Musca vetustissima Wlk., the Australian bushfly, was determined as a function of age and size from an analysis of the age-size distribution of 11 530 females caught over a period of four years at three sites in south-eastern Australia. The mean length of life of the largest female flies commonly observed in the field was about 15·5 egg-stage periods, as compared to 8·5 for the smallest flies commonly observed. Over the same range of sizes, the breeding potential of a female varied by a factor of 22 to 1. It was found that the attractiveness of a human observer as a bait to female flies varied with the flies' reproductive state; taking the attractiveness to newly emerged flies to be unity, the attractiveness of the observer to flies that had just laid eggs was 1·22, and to flies in the pre-gravid stage 0·15. The mathematical model presented in this paper is appropriate for use in an overall model of bushfly population dynamics.