D3097: The effect of weather on the accuracy of phenological predictions for European spongy moth

The spongy moth, Lymantria dispar dispar (L.) (Lepidoptera: Erebidae), is a non-native insect that, following its establishment in the late 1800s, has spread throughout multiple states and provinces in eastern North America. The Slow the Spread (STS) Program was launched in the early 2000s to contain the expansion of this species in order to reduce its economic and ecological damage. Several STS management strategies, such as mating disruption and spraying of Btk (Bacillus thuringiensis kurstaki), are guided by the spongy moth life stage (GLS) model, which predicts the seasonality of each spongy moth life stage based on local meteorological conditions. However, the GLS model's accuracy has yet to be evaluated over a large geographic scale. Using a multi-year dataset, we assessed the GLS model's performance by comparing predictions of male moth flight with observed male moth captures across the leading edge of the invasion, an area that comprises various climatic regimes. Additionally, we aimed to elucidate how abiotic factors (e.g., temperature, photoperiod, and their interaction) affect the prediction accuracy of the model. Our findings provide insights into the spatiotemporal robustness of the GLS model and the conditions that impact model accuracy, both of which have implications for the efficacy of STS interventions.