Abstract
Mythimna separata (Walker) moths captured in light traps were monitored in Luohe, central‐northern China, from 1980 to 2016. Annual average temperature recorded an increase of 0.298°C/10 years in this region in the period. Our results indicate that a rising April and May average temperature and earlier occurrences of days recording the highest day temperature (30°C) caused an advanced peak and increasing proportion of high ovarian development levels of first‐generation females in earlier summers. Results using Johnson's formulation of “oogenesis‐flight syndrome” indicate that increasing sexual maturity proportion has resulted in more emigrant individuals in the local first‐generation moth becoming residents, and then increased individuals rapidly in the local second‐generation moth since 2006. Consequences of this action have a boom in corn damage since 2007 in this region. Advanced peak dates of the first and second‐generation moth revealed the same response to increasing average monthly temperatures in the monitoring period. Increasing temperatures, the average May temperature exceeds or equal to 22°C, during the early 2000's may represent a physiological threshold for M. separata development. Our results suggest that climate warming may impact M. separata migratory status and cause a problem of crop production in this region.
Highlights
The oriental armyworm, Mythimna separata (Walker), is a seasonal migratory insect pest that frequently causes serious widespread loss or even disasters in cereal crops in China and East Asia (Li, Wang, & Hu, 1964)
Previous studies have reported that M. separata has four seasonal migrations in multigeneration between southern overwin‐ tering areas and northern areas every year in China
The second northward migration occurs in early summer, ranging from central‐northern China to north and northeastern China
Summary
The oriental armyworm, Mythimna separata (Walker), is a seasonal migratory insect pest that frequently causes serious widespread loss or even disasters in cereal crops in China and East Asia (Li, Wang, & Hu, 1964). Previous studies have reported that M. separata has four seasonal migrations in multigeneration between southern overwin‐ tering areas and northern areas every year in China. These migration episodes include two northern events (in spring and early summer) and two southern events (in the fall; Chen, Sun, Wang, Zhai, & Bao, 1995; Li et al, 1964; Wu, Cheng, Xu, Zhai, & Guo, 2001). The second northward migration occurs in early summer, ranging from central‐northern China to north and northeastern China Generation individuals in this migra‐ tion rarely remain and damage summer corn in the migration area, the central‐northern region (Feng et al, 2008; Li et al, 1964; Zhao et al, 2009). Changes in the summer migratory status of M. separata should be evaluated for their impact on human activities and environmental change
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
