The spring migration behavior of the oriental armyworm, Mythimna separata, in northeastern China
Author of the article:GAO Yue-Bo** SUN Ya-Jie ZHANG Qiang SUN Wei ZHOU Jia-Chun
Author's Workplace：Key Laboratory of Integrated Pest Management on Crops in Northeast, Ministry of Agriculture, Institute of Plant Protection,Jilin Academy of Agricultural Sciences, Gongzhuling 136100, China
Key Words：Mythimna separata, migration, common orientation, stratification, behavior mechanism
Abstract： To investigate the aerial stratification and common orientation of the spring migrant populations of the oriental armyworm Mythimna separata (Walker). [Methods] This study is based on spring radar data collected over two years, in combination with the analysis of meteorological factors and compass cues. [Results] Most moths trended to aggregate near the upper inversion surface in order to find warmer conditions. Moreover, M. separata moths had a lower temperature threshold (about16°C) during the migration period when it had low population density and did not to aggregate under this temperature threshold. Furthermore, a significant correlation between migration direction and the wind speed was observed. When the wind was strong (>5 m/s) and closely aligned with the armyworm moths heading (i.e., toward the NE), M. separata generally orientated close to the downwind. When the wind speed was less (<3 m/s) and not closely aligned with the moths heading, M. separata compensated for the cross-wind drift and even flew upwind. On the other hand, the oriental armyworm may use some compass cues (e.g., geomagnetic compass) to orient its general flight direction, during migration. [Conclusion] The results provide some theoretical basis for the off-site forecasting of migratory insect pests.