Bifurcation analysis in delayed Nicholson blowflies equation with delayed harvest

In this paper, we investigate a delayed Nicholson equation with delay harvesting term which was proposed in open problems and conjectures formulated by Berezansky et al. (Appl. Math. Model. 34: 1405–1417, 2010). The stability switching curves taking two delays as parameters are obtained via the method introduced An al.(J. Differ. Equ. 266: 7073–7100, 2019). existence of Hopf singularity on two-parameter plane is determined varying direction parameters. Furthermore, normal form near derived applying center manifolds theory forms FDEs. Finally, some numerical simulations carried out to illustrate theoretical conclusions.