摘要:A three-species Lotka-Volterra system with impulsive control strategies containing
the biological control (the constant impulse) and the chemical control (the proportional
impulse) with the same period, but not simultaneously, is investigated. By
applying the Floquet theory of impulsive differential equation and small amplitude
perturbation techniques to the system, we find conditions for local and global stabilities
of a lower-level prey and top-predator free periodic solution of the system. In
addition, it is shown that the system is permanent under some conditions by using
comparison results of impulsive differential inequalities. We also give a numerical
example that seems to indicate the existence of chaotic behavior.