Multiple periodic solutions for a non-autonomous delayed predator–prey model with harvesting terms

By using the generalized continuation theorem, the existence of at least two positive periodic solutions for a non-autonomous delayed periodic predator–prey model with harvestingx′(t)=x(t)[r(t)-a(t)x(t)]-b(t)x(t)m+x(t)y(t)-h1(t),y′(t)=y(t)c(t)x(t-τ(t))m+x(t-τ(t))-d(t)-h2(t)is established. The method used here is more convenient than Mawhin’s continuation theorem. And the main results show that the harvesting terms consult in the additional periodic solution.