This study evaluated the potential distribution of the potato tuber moth. This species severely impacts global potato production, especially in China and India, which have the world’s largest potato production. We developed two indices considering host plant availability and production in addition to climatic suitability, which was simulated using the CLIMEX model. Thus, three different indices were used to project potential distribution of the potato tuber moth under a climate change scenario: (1) climatic suitability (ecoclimatic index (EI)) (EI_M), (2) climatic suitability combined with host plant availability (EI_N1), and (3) climatic suitability combined with host plant production (EI_N2). Under the current climate, EI_M was high in southern India and central to southern China, while EI_N1 and EI_N2 were approximately 38% and 20% lower than EI_M, respectively. Under the Special Report on Emissions Scenario A1B, the potato tuber moth would probably not occur in India, but its distribution could be extended to the north, reaching N47°. The areas with the highest climatic suitability by potato tuber moth based on three indices were Sichuan and Karnataka in response to climate change. These areas require adequate pest control, such as prevention of spread through transport of potato seed or by using cold storage facilities.

Potato tuber moth (Phthorimaea operculella), one of the leading potato-damaging pests in the world, has caused severe damage to potato production in South Korea after its introduction in the 1960s. This study surveyed the field occurrence of potato tuber moth in various sites in South Korea and used the results to validate the CLIMEX model, which spatiotemporally evaluated the potential distribution of potato tuber moths in response to climate change. The potato tuber moths were predicted to appear throughout the country, consistent with the results obtained for potato tuber moths in 96% of the field survey area. In addition, the climatic suitability of potato tuber moths will remain high due to climate change, suggesting a high risk for damage to seasonal potato production from seeding to harvesting. This spatiotemporal assessment of potato tuber moth distribution is expected to aid in establishing control strategies optimized based on time and place.