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The Spotted Lantern Fly (SLF), Lycorma delicatula (Hemiptera: Fulgoridae), is a sap feeding pest native to southeast Asia that has become a global biosecurity threat following invasions into South Korea, Japan, and the United States in the last two decades. Environmental niche modelling has demonstrated considerable potential for further range expansions, including into Australia and Europe. Further analysis on the potential seasonal life-history and survival of this pest in its invasive range can inform monitoring programs and is a next step in biosecurity preparedness. Here, we incorporated eco-physiological information on the development and survival of SLF life stages across temperature regimes. Using gridded climatic data, we then mapped the developmental sequence of SLF across ranges already occupied in China, South Korea, and the United States, as well as uninvaded ranges in Australia and Europe. The model was able to capture global observations of the seasonal appearance of SLF and highlight regional and seasonal vulnerabilities in regions at risk of invasion. Policy makers can use these results to make science-based biosecurity decisions and target preparedness activities through improved life-history predictions in its invasive range.

BACKGROUND: The global pest spotted winged drosophila (Drosophila suzukii) continues to have a significant economic impact on fruit production in areas where it is established, in addition to newly invaded ranges. Management activities spanning national biosecurity responses to farm-scale pest control are limited by the inability to predict the timing and severity of seasonal outbreaks of D. suzukii and its climatic drivers. RESULTS: Here, we compiled and analysed data on international seasonal abundances for D. suzukii under different climates, crop types and management contexts to improve the predictability of seasonal population dynamics. In relating seasonal abundances to environmental predictors, specifically temperature, we found strong negative effects of exposure to high and low temperatures during the preceding month. Unlike most regional studies on D. suzukii phenology that focus on temperature in the physiological development range, we show that thermal extremes better explain seasonal population fluctuations. CONCLUSION: Although trap catches remain an indirect measure of infestations and must be interpreted carefully in terms of crop risk, our results should support monitoring programmes through enhanced knowledge of the climatic factors affecting D. suzukii population activity. The negative impact of high temperatures suggests that late-season management strategies focusing on manipulating crop microclimates to temperatures above 25 °C can reduce D. suzukii abundance. We show that early season abundance is modulated by climate, particularly the depth of cold extremes experienced in the preceding time interval. These associations may be further developed into early-season crop risk forecasts to support monitoring programs. © 2021 Society of Chemical Industry.