PHYTOSEIID LIFE-HISTORIES, LOCAL PREDATOR-PREY DYNAMICS, AND STRATEGIES FOR CONTROL OF TETRANYCHID MITES

Numerous studies have been devoted to estimating the intrinsic rates of increase, r(m), of phytoseiid and tetranychid mites. Intrinsic rates of increase may be helpful for biological control purposes, but how exactly is still unclear. In this paper, we show how r(m)s can be used to this end, by using a simple model for the local dynamics of predator and prey populations. The application of this model critically depends on what is meant by the term local. Here, we define it as a spatial scale at which predator and prey dynamics are strongly coupled. Furthermore, it is shown that the r(m) of phytoseiid and tetranychid mites are correlated with mean and peak oviposition rates. Since peak oviposition rates are easy to determine, the regression equation provides a quick and simple way to estimate r(m). Subsequently, it is possible to calculate appropriate predator/prey ratios for biological control by using the model and the estimated r(m).