Modelling the trappability of tsetse, Glossina fuscipes fuscipes, in relation to distance from their natural habitats

The log–logistic probability distribution function was employed to model trappability of Glossina fuscipes fuscipes, with respect to distance from the edge of two types of habitat. The parameters of the model were obtained using the nonlinear maximum likelihood approach. Asymptotic standard errors of the maximum likelihood estimates were computed for the parameters, and the χ2 goodness-of-fit test used to assess the predicted trap catches. Simulation technique was used to estimate the radius of attraction of the unbaited biconical trap for the fly, taking the efficiency of the trap into consideration. The log–logistic model fitted well to a series of observed field data. The model enabled the estimation of optimum trapping distances from the different habitat types for G. f. fuscipes. There is an indication that flies were attracted to, and got trapped optimally with, unbaited biconical traps, at distances that are characteristic of both sex of the fly and the type of habitat.