Physics and Astronomy Department, Haverford College, Haverford, PA 19041, USA.
Department of Biology, Temple University, Philadelphia, PA 19122, USA.
J Exp Biol. 2023 Oct 1;226(19). doi: 10.1242/jeb.246340. Epub 2023 Oct 6.
How animals jump and land on diverse surfaces is ecologically important and relevant to bioinspired robotics. Here, we describe the jumping biomechanics of the planthopper Lycorma delicatula (spotted lanternfly), an invasive insect in the USA that jumps frequently for dispersal, locomotion and predator evasion. High-speed video was used to analyze jumping by spotted lanternfly nymphs from take-off to impact on compliant surfaces. These insects used rapid hindleg extensions to achieve high take-off speeds (2.7-3.4 m s-1) and accelerations (800-1000 m s-2), with mid-air trajectories consistent with ballistic motion without drag forces or steering. Despite rotating rapidly (5-45 Hz) about time-varying axes of rotation, they landed successfully in 58.9% of trials. They also attained the most successful impact orientation significantly more often than predicted by chance, consistent with their using attitude control. Notably, these insects were able to land successfully when impacting surfaces at all angles, pointing to the importance of collisional recovery behaviors. To further understand their rotational dynamics, we created realistic 3D rendered models of spotted lanternflies and used them to compute their mechanical properties during jumping. Computer simulations based on these models and drag torques estimated from fits to tracked data successfully predicted several features of the measured rotational kinematics. This analysis showed that the rotational inertia of spotted lanternfly nymphs is predominantly due to their legs, enabling them to use posture changes as well as drag torque to control their angular velocity, and hence their orientation, thereby facilitating predominately successful landings when jumping.
动物如何在不同的表面上跳跃和着陆在生态学上是很重要的，并且与仿生机器人学有关。在这里，我们描述了斑衣蜡蝉（美国白蛾）的跳跃生物力学，这是一种在美国入侵的昆虫，经常跳跃以进行扩散、运动和逃避捕食者。高速视频被用于分析斑衣蜡蝉若虫从起飞到撞击柔性表面的跳跃。这些昆虫利用快速的后腿伸展来实现高起飞速度（2.7-3.4 m/s）和加速度（800-1000 m/s2），在空中轨迹与没有阻力或转向的弹道运动一致。尽管它们以随时间变化的旋转轴快速旋转（5-45 Hz），但在 58.9%的试验中它们还是成功着陆。它们还以比随机预测更频繁的方式达到了最成功的撞击方向，这与它们使用姿态控制是一致的。值得注意的是，这些昆虫在以各种角度撞击表面时都能成功着陆，这表明碰撞恢复行为的重要性。为了进一步了解它们的旋转动力学，我们创建了斑衣蜡蝉的逼真 3D 渲染模型，并使用它们来计算它们在跳跃过程中的力学特性。基于这些模型和从跟踪数据拟合估计的阻力扭矩的计算机模拟成功地预测了测量的旋转运动学的几个特征。这项分析表明，斑衣蜡蝉若虫的转动惯量主要是由于它们的腿，使它们能够利用姿势变化以及阻力扭矩来控制它们的角速度，从而在跳跃时更容易成功着陆。
