  In this paper, we investigate the global existence of almost surely positive
solution to a stochastic Nicholson's blowflies delay differential equation with
regime switching, and give the estimation of the path. The results presented in
this paper extend some corresponding results in Wang et al. Stochastic
Nicholson's Blowflies Delayed Differential Equations, Appl. Math. Lett. 87
(2019) 20-26.
