New results on periodic solutions of delayed Nicholson's blowflies models

Abstract

This paper is concerned with a class of Nicholson's blowflies models with a nonlinear density-dependent mortality term. We use coincidence degree theory and give several sufficient conditions which guarantee the existence of positive periodic solutions of the model. Moreover, we give an example to illustrate our main results.

Keywords

• nicholson's blowflies model
• positive periodic solution
• coincidence degree
• nonlinear density-dependent mortality term