Abstract: The oriental armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae), is a major migrant pest of grain in China and other Asian countries, causing huge crop production and economic losses nationwide annually.  Much of the uniquely difficult aspects of managing M. separata arises from its long-distance migratory behavior.  For example, direction and timing of winds from its overwintering regions in the south largely determine where and when large influxes of migrants arrive in the north to oviposit, making prediction of infestations difficult.  Since the 1960s, the migration routes and infestation patterns of M. separata in China have been resolved (Li et al. 1964; Jiang et al. 2011), allowing development of effective forecasting and early warning technology to help manage this insect.  Over the past two decades, large-scale outbreaks of M. separata have rarely occurred.  However, in 2012, M. separata infested much of northern and northeastern China.
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We hope that the readers will find the articles in this special focus informative and useful for oriental armyworm pest management.  We are grateful to the authors and anonymous reviewers.  We thank Editorial Board and Editor-in-Chief of the Journal of Integrative Agriculture for accepting our proposal to publish these papers.  We also thank the special fund for Agro-scientific Research in the Public Interest of China (201403031) for support of this special focus.