Change in the distribution of the potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), in Korea

Abstract Having originated in Latin America and co-evolved with its host plant potato ( Solanum sp .), the potato tuber moth (PTM), Phthorimaea operculella (Zeller), has become one of the most serious insect pests around the world, including in Korea. The PTM was introduced to Japan in the 1960s, and because of an outbreak in 1970s, it has been intensively surveyed two years (1978 and 1979, Choe and Park, 1980) in the Korean peninsula. The results of this survey showed that the PTM was only distributed over most of the southern part of the peninsula. Over the past 30 years, the PTM has not been a main pest in the central part of Korea. However, there was again a PTM outbreak in the late 2000s not only in the Southern but also central part of the peninsula. Therefore, we conducted an intensive incidence survey of the PTM on potato crops at 37 locations during 2009–2012 in South Korea. The distribution of the PTM expanded by 200 km into the northern parts within three decades. Many factors could have contributed to the changes in the PTM distribution, such as climate, traffic, cultivar identity, fauna and flora. Among them, we hypothesized that temperature is one of the main factors because the mean temperature increased by approximately 0.9 °C during that time. In recent years, the temperature has been steadily rising due to climate change, and it is predicted that the occurrence of the PTM will continue to increase in the future. Therefore, the development of control technologies and intensive monitoring will be necessary for stable potato production as well as potato post-harvest.