Betz O, Mumm R
Zoologisches Institut der Universität, Okologie, Olshausenstr. 40, 24098 Kiel, Germany.
Arthropod Struct Dev. 2001 Nov;30(2):77-97. doi: 10.1016/s1467-8039(01)00029-9.
Representatives of the staphylinid beetle Philonthus marginatus are characterized by highly modified raptorial forelegs which are used to strike prey in a particularly fast manner. Beetles ready to capture prey remain in a characteristic precapture ambush posture characterized by lifted and folded forelegs. Triggered by sensory input from the antenna or other parts of the fore body, the actual strike is released, essentially taking the form of a rapid (about 9 ms) depression of the unfolding forelegs towards the prey. This movement is based on the presence of a coxo-trochanteral catch mechanism and a particularly wide angle of rotation in the coxo-trochanteral joint. It is made possible by the specific mechanics of this joint which probably also involves a co-contraction of the antagonistic trochantero-femoral flexor and extensor muscles suggesting a spring-loaded system. This phase of the strike is immediately followed by fixation of the prey by the ventral adhesive tarsal setae supported by a grasp of the flexing last tarsomere and the claws. After withdrawal of the forelegs together with the prey, the sequence eventually results in the formation of a capture-basket formed frontally by the perpendicularly flexing head and laterally by the spiny inner sides of the coxae.
边缘隐翅虫（Philonthus marginatus）的代表特征是其高度特化的捕食性前腿，这些前腿用于以特别快的方式攻击猎物。准备捕捉猎物的甲虫会保持一种典型的捕食前伏击姿势，其特征是前腿抬起并折叠。由触角或前体其他部位的感官输入触发，实际的攻击被释放，基本上表现为展开的前腿朝着猎物快速（约9毫秒）下压的形式。这种运动基于一个基节 - 转节捕捉机制以及基节 - 转节关节中特别大的旋转角度。这种关节的特殊力学结构使其成为可能，这可能还涉及到对抗性的转节 - 股骨屈肌和伸肌的协同收缩，表明这是一个弹簧加载系统。攻击的这个阶段紧接着是通过腹侧粘性跗节刚毛固定猎物，这由弯曲的末节跗骨和爪子的抓握来支撑。前腿与猎物一起撤回后，这个序列最终导致形成一个捕捉篮，其前部由垂直弯曲的头部形成，侧面由基节多刺的内侧形成。
