THEORETICAL DYNAMICS OF EXPERIMENTAL POPULATIONS OF INTRODUCED AND NATIVE BLOWFLIES (DIPTERA, CALLIPHORIDAE)

Equilibrium dynamics in experimental populations of Chrysomya megaceph ala (F.) and C. putoria (Wiedemann), which have recently invaded the A mericas, and the native species Cochliomyia macellaria (F.), were inve stigated using nonlinear difference equations. A theoretical analysis of the mathematical model using bifurcation theory established-the com bination of demographic parameters responsible for producing shifts in blowfly population dynamics from stable equilibria to bounded cycles and aperiodic behavior. Mathematical modeling shows that the populatio ns of the 2 introduced Chrysomya species will form stable oscillations with numbers fluctuating 3-4 times in successive generations. However , in the native species C. macellaria, the dynamics is characterized b y damping oscillations in population size, leading to a stable populat ion level.