<p>Host-parasitoid interactions play a crucial role in ecological dynamics and have been widely studied in population biology. This study focuses on the existence of weak solutions for time-fractional host-parasitoid systems described by partial differential equations with nonlinear diffusion. The partial differential equation model under consideration incorporates the diffusion term to capture the spatial dynamics of the interacting populations. However, the presence of non-linearity in the diffusion term poses challenges in establishing the existence of solutions. In this study, we employ the theory of weak solutions to analyze the partial differential equation model and investigate the existence of solutions that satisfy the given boundary and initial conditions. We use the Galerkin method to prove the existence of weak solutions. The results contribute to a deeper understanding of the dynamics of host-parasitoid systems and offer valuable insights to ecological modeling and conservation strategies.</p>