粘虫飞行定向行为与不同磁场环境的关系

Effect of magnetic fields on the orientation behavior of the oriental armyworm Mythimna separata(Walker)

【目的】研究正常地磁场和近零磁场条件下饲养的粘虫Mythimna separata(Walker)夜间飞行定向行为与磁场的关系,为明确迁飞性昆虫远距离迁飞的地磁定向机制提供依据。【方法】分别在正常地磁场和近零磁场条件饲养粘虫,羽化后的粘虫蛾在人工模拟不同的磁场条件下进行夜间飞行定向行为测试,比较粘虫蛾飞行定向行为的差异。【结果】粘虫蛾在正常地磁场条件下均具有显著的群体共同定向行为,夏季测试的粘虫群体共同定向方向为偏北;在近零磁场以及垂直平面分量倒转的地磁场条件下,粘虫蛾群体共同定向行为均消失。同时,不同磁场的生长环境对粘虫飞行定向行为的影响不明显,而飞行测试时的磁场环境对其定向行为有显著影响。【结论】磁场可能是粘虫定向的重要参考依据之一,粘虫对地磁场磁倾角的变化有反应,推测其可能利用了磁倾角进行一定程度上的辅助定向。

[Objectives] To clarify the effect of magnetic fields on the nocturnal orientation behavior of Mythimna separata(Walker) and investigate the magnetic orientation mechanisms of aerial migratory insects. [Methods] Oriental armyworms were raised in geomagnetic and near-zero magnetic fields, and experiments on the orientation behavior of oriental armyworm moths were carried out in an artificial simulated magnetic field. [Results] M. separata exhibited significant group orientation with respect to geomagnetic field, which in summer was northward. This common group orientation disappeared under near-zero magnetic field conditions and the vertical variable of geomagnetic field reversal. The growth environment under different magnetic fields had little effect on orientation behavior, but the magnetic field environment had a notable influence on flight direction. [Conclusion] The orientation of M. separata is clearly affected by magnetic field and nocturnal aerial migratory insects may use magnetic fields for navigation.