Data from: Listening to the environment: hearing differences from an epigenetic effect in solitarious and gregarious locusts

Locusts display a striking form of phenotypic plasticity, developing into either a lone-living solitarious phase or a swarming gregarious phase depending on population density. The two phases differ extensively in appearance, behaviour, and physiology. We found that solitarious and gregarious locusts have clear differences in their hearing, both in their tympanal and neuronal responses. We identified significant differences in the shape of the tympana that may be responsible for the variations in hearing between locust phases. We measured the nanometre mechanical responses of the ear’s tympanal membrane to sound, finding that solitarious animals exhibit greater displacement. Finally, neural experiments signified that solitarious locusts have a relatively stronger response to high frequencies. The enhanced response to high frequency sounds in the nocturnally flying solitarious locusts suggests greater investment in detecting the ultrasonic echolocation calls of bats, to which they are more vulnerable than diurnally active gregarious locusts. This study highlights the importance of epigenetic effects set forth during development and begins to identify how animals are equipped to match their immediate environmental needs.蝗虫展现出极为显著的表型可塑性（phenotypic plasticity）：依据种群密度的不同，可发育为独居的散居型（solitarious phase）或是集群的群居型（gregarious phase）。两种型态在外观、行为与生理层面均存在显著差异。本研究发现，散居型与群居型蝗虫的听觉系统存在明确差异，具体体现为鼓膜响应与神经元响应两方面。我们已证实蝗虫鼓膜的形态存在显著差异，这或可解释不同型态蝗虫听觉特性的差异来源。我们测定了听觉器官鼓膜对声波的纳米级机械响应，结果显示散居型蝗虫的鼓膜位移量更大。此外，神经元实验结果表明，散居型蝗虫对高频声波的响应相对更强。夜行性飞行的散居型蝗虫对高频声波的响应更为强烈，这提示它们更倾向于投入更多资源来侦测蝙蝠的超声回声定位叫声——相较于昼行性的群居型蝗虫，散居型蝗虫更易受到蝙蝠的攻击。本研究凸显了发育过程中表观遗传效应（epigenetic effects）的重要性，并初步揭示了动物如何演化出适配即时环境需求的生理机制。