Wing mechanics and acoustic communication of a new genus of sylvan katydid (Orthoptera: Tettigoniidae: Pseudophyllinae) from the Central Cordillera cloud forest of Colombia

Stridulation is used by male katydids to produce sound via the rubbing together of their specialised forewings, either by sustained or interrupted sweeps of the file producing different tones and call structures. This study aims to measure and quantify the mechanics of wing vibration, sound production and acoustic properties of the hearing system in a new genus of Pseudophyllinae. The calling behaviour and wing mechanics of males were studied using micro-scanning laser Doppler vibrometry, microscopy, and ultrasound sensitive equipment. The resonant properties of the acoustic pinnae of the ears were obtained via μ-CT scanning and 3D printed experimentation. Analysis of sound recordings and wing vibrations reveal that the stridulatory areas of the right tegmen exhibit relatively narrow frequency responses and produce narrowband calls between 12 and 20 kHz. As in most Pseudophyllinae, only the right mirror is activated for sound production. The acoustic pinnae of all species were found to provide a broadband increased acoustic gain from ~40 - 120 kHz, by up to 25 dB. Under laboratory conditions the calling song duty cycle is relatively constant, with males spending most of the night singing from the burrows they guard and protect. The new genus, named Satizabalus, is here derived as a new polytypic genus from the existing genus Gnathoclita, based on morphological and acoustic evidence from one described (S. sodalis) and two new species (S. jorgevargasi, S. hauca). Unlike most Tettigoniids, Satizabalus exhibits a particular form of sexual dimorphism whereby the heads and mandibles of the males are greatly enlarged compared to the females. We suggest that Satizabalus is related to the genus Trichotettix, also found in cloud forests in Colombia, and not to Gnathoclita.

摩擦发声（stridulation）是雄性螽斯通过特化前翅相互摩擦产生声音的行为：通过其锉状发声结构的持续或间断扫动，可产生不同音调与鸣唱结构。本研究旨在对露螽亚科（Pseudophyllinae）的一个新属类群，开展翅振动力学、声音产生机制以及听觉系统声学特性的测量与量化分析。
研究人员采用显微扫描激光多普勒测振仪（micro-scanning laser Doppler vibrometry）、显微成像技术以及超声敏感设备，对该类群雄性的鸣唱行为与翅部力学特性进行了研究。通过微计算机断层扫描（μ-CT）与3D打印实验，获取了其耳部听觉突（acoustic pinnae）的共振特性。
对声音录制结果与翅部振动的分析显示，右翼覆翅的摩擦发声区域展现出较窄的频率响应，并可产生12至20 kHz之间的窄带鸣唱信号。与多数露螽亚科物种一致，该类群仅激活右侧鸣镜（mirror）以完成发声过程。
所有受试物种的听觉突均可实现约40至120 kHz频段的宽频声学增益，最大增益可达25 dB。在实验室条件下，其鸣唱歌曲的占空比相对稳定，雄性个体夜间多数时间都会在其守卫的洞穴中进行鸣唱。
本研究基于1个已描述物种（"S. sodalis"）与2个新物种（"S. jorgevargasi"、"S. hauca"）的形态学与声学证据，将该新属从现有颚螽属（Gnathoclita）中分出，建立新的多型属，命名为萨氏螽属（Satizabalus）。
与多数螽斯物种不同，萨氏螽属展现出一种特殊的雌雄二型性：雄性个体的头部与上颚远较雌性更为发达。研究认为萨氏螽属与同样分布于哥伦比亚云雾林的毛螽属（Trichotettix）具有亲缘关系，而非与颚螽属近缘。