Crops in Southern Part of Northern China, Ministry of Agriculture; Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengzhou450002, China) Global warming and climate change are likely to trigger changes in geographical distribution and overwintering region of insect pests. The northern boundary of overwintering for pink stem borer, Sesamia inferens (Walker) (Lepidoptera: Noctuidae) was at 34° north latitude in 1980s. Recently, occurrence and damage of S. inferens on summer corn seedlings has been first observed in wheat-maize rotation region of Xinxiang (35° north latitude), northern Henan Province. In order to develop a sound forecasting and management program in summer corn region of China, population dynamics and life history of S. inferens were investigated in Xinxiang from 2014 to 2015. The results indicated that S. inferens could finish its life history and damage on ears of summer corn in Xinxiang, which was the first report about its northern boundary in China. Light traps and field surveys showed there were three generations per year for S. inferens in this area. The overwintering larvae pupated and emerged in mid to late April, and then female adults laid eggs on winter wheat and spring corn. Larvae of the first generation damaged winter wheat and spring corn in late May and early June and mature larvae of this generation pupated and emerged after mid-June. The moths of the first generation transferred into summer corn field and oviposited in corn seedling for continuous life cycle. Larvae of the second generation damaged seedling after mid-July. S. inferens larvae of the third generation (overwintering generation) damaged the stem and ear in summer corn field and drilled into the root of corn stalk for overwintering in late September. An annual life history table for the S. inferens in northern Henan Province was drawn based on these observed data.