Figure 2

Dynamical behavior of (1.2). (a) is for (1.2) with \(\xi _{1}=0.8\), \(\xi _{2}=0.4\), \(\xi _{3}=0.01\), then \(\lim_{t\rightarrow \infty }N_{1}(t)=0\), \(\lim_{t \rightarrow \infty }\langle N_{2}(t)\rangle =0.5471\), \(\lim_{t \rightarrow \infty }\langle N_{3}(t)\rangle =0.1118\), (b) is for (1.2) with \(r_{3}=0.1\), \(\xi _{1}=0.8\), \(\xi _{2}=0.469\), \(\xi _{3}=0.01\), then \(N_{1}(t)\), \(N_{3}(t) \) are both extinct, \(\lim_{t\rightarrow \infty }\langle N_{2}(t)\rangle =0.5\)