Impact of Nutrient Limitation on Nezara viridula Development: Validation of a Stage‐Structured Degree‐Day Model in Outdoor and Greenhouse Environments Using Citizen Science Data

ABSTRACT Nezara viridula (L.) (Hemiptera: Pentatomidae) is a significant pest affecting crops in both outdoor and greenhouse environments. To improve pest management strategies, we validated and compared two degree‐day models predicting N. viridula development using citizen science occurrence records, greenhouse observations, and laboratory trials. Model 1, based on literature data from high‐protein diets, was tested against Model 2, which accounts for slower development in nutrient‐limited conditions. Citizen science records, collected via biodiversity platforms, provided insights into N. viridula 's natural occurrence, while laboratory trials investigated its development on different food sources, including beans, peppers, and nuts. In natural conditions, Model 1 accurately predicted first appearance dates and population dynamics. However, in greenhouse environments, where nutrient availability is more limited, Model 2 performed better, correctly predicting two observed generations, while Model 1 overestimated the number of generations. Although RMSE and MAE metrics quantified model accuracy, visual inspection highlighted developmental trends that were not fully captured by these metrics alone. Greenhouse environments are suboptimal for N. viridula , primarily due to limited protein availability in monocultures like peppers, restricting the population to two generations per year. This finding suggests that new biocontrol strategies could exploit these suboptimal conditions to effectively manage pest populations. Further refinement of these models is needed to better account for all factors influencing development rates, especially in controlled environments.