In this paper, we investigate the dynamics of a time-delay ratio-dependent predator-prey model with stage structure for the predator. This predator-prey system conforms to the realistically biological environment. The existence and stability of the positive equilibrium are thoroughly analyzed, and the sufficient and necessary conditions for the stability and instability of the positive equilibrium are obtained for the case without delay. Then, the influence of delay on the dynamics of the system is investigated using the geometric criterion developed by Beretta and Kuang. 26 We show that the positive steady state can be destabilized through a Hopf bifurcation and there exist stability switches under some conditions. The formulas determining the direction and the stability of Hopf bifurcations are explicitly derived by using the center manifold reduction and normal form theory. Finally, some numerical simulations are performed to illustrate and expand our theoretical results.
KEYWORDSHopf bifurcation, predator-prey model, stage structure, delay, stability switches
), which implies that the functional response function depends on the ratio of the prey x(t) to the predator y(t). The ratio-dependent functional response function contains obviously biological significance, because the predators often compete among themselves, and the per capita rate of predation depends on the numbers of both predators and preys, Math Meth Appl Sci. 2017;40:6451-6467.wileyonlinelibrary.com/journal/mma