Overcoming challenges in model selection and parameter estimation in functional response studies with parasitoids: a practical guide

Parasitoids play a key role in biological control, regulating pest populations in natural and agricultural ecosystems. Their efficiency depends on a thorough understanding of host-parasitoid interactions. Among these, the functional response, the relationship between parasitism rate and host density, plays a critical role. Despite a well-established background, challenges remain in experimental design, model selection, and parameter estimation for functional response analysis in parasitoids. This study aims to provide a practical guide to addressing these challenges. We outline key considerations in experimental design, including the selection of model organisms and initial host densities. For model selection, we present methods to differentiate between Type II and Type III functional responses, identifying the best-fitting models for parasitoids. In parameter estimation, we present an example demonstrating the application of functional response models for each type, including parameter estimation to guide model choice. Additionally, we provide equations and code based on published data to facilitate parameter comparisons. This guide provides a structured framework for experimental design, parameter estimation, and model selection in functional response studies, which is adaptable to various host-parasitoid interactions. By enhancing methodological rigour, we aim to support researchers in improving the precision and applicability of functional response analyses in parasitoid research.