ARCASIM, a model to evaluate augmentation strategies of the parasitoid Catolaccus grandis against boll weevil populations

An age structured computer simulation model (ARCASIM) was created to understand the complexities of the interactions between cotton fruiting and population dynamics of the boll weevil (Anthonomus grandis Boheman) and its parasitoid Catolaccus grandis (Burks). Strategies for the use of augmentative releases of C. grandis against infestations of the boll weevil were developed based on the simulations. The model indicates that releases of the parasitoid done at weekly intervals is a better strategy than use of a single release at an optimal time. The simulations revealed that the density of immigrating adult boll weevils into the release area is the most important factor in determining whether or not augmentative releases of C. grandis will be effective. Yield losses and boll weevil mortality by parasitism are not totally correlated. The model showed that cultivation practices can effectively disrupt the control of boll weevil by augmentative releases of C. grandis.