Two methods of estimating competitiveness of chemosterilized males of Musca domestica (Diptera: Muscidae)

Abstract

Mating competitiveness and sexual or total competitiveness of males of the house fly, Musca domestica Linnaeus, treated with 1.0% hexamethyl phosphoramide (hempa) were measured quantitatively from direct observations and ratio test methods, respectively. From direct observations, treated males of Cooper and Boxted strains of M. domestica were found to obtain more first matings than untreated males (P <0.01 and P <0.05, respectively) when competing for untreated females, whilst by using the ratio test method under laboratory conditions, total competitiveness values (C) of treated males of the two strains were estimated to be 0.72–0.89 and 0.75–0.97, respectively, at three different ratios from 1:1:1 to 3:1:1.