Despite rising global concerns over the potential impacts of invasive alien species on indigenous species, the consequences of such introductions are lacking. The cabbage seedpod weevil (CSPW, C. obstrictus) was introduced into Korea in the early of 1990s. There was no genetic differences of COI sequences between populations of invasive CSPW, while was 1.1 % between populations of native rapeseed weevil (RSW, C. albosuturalis). It is tentatively considered that CSPW spread from once invasive population to the whole country. A large-scale survey in Korea reveals that, in about 20 years post-arrival, the invasive CSPW has become the most abundant on rape flowers and spread almost parts of South Korea including Is. Jeju and Is. Ulleung. Its spread is concurrent with the geographic retraction of the native RSW. However, Is. Yeoseo located between the mainland and Is. Jeju, was showed their ratio with 1:1. It suggests that the population of CSPW recently entered this island. Although the decline’s underlying mechanisms remain unknown, the potential roles of exploitative competition cannot be ruled out. Given that invasive weevil can rapidly replace native congeners, further introductions of other insect pests should be discouraged.

• Kyongyoung Kim(Department of Plant Medicine, Sunchon National University)
• Wonhoon Lee(Department of Plant Medicine and Institute of Agriculture & Life Science, Gyeongsang National University)
• Doo-Sang Park(Biological Resource Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB))
• Ki-Jeong Hong(Department of Plant Medicine, Sunchon National University)