Many of the existing winged-insect species are extremely small (wing $\text{length}\approx 0.3–4\mathrm{mm}$); they are referred to as miniature insects. Yet, until recently much of our knowledge about the mechanics of insect flight was derived from studies on relatively large insects, such as flies, honeybees, hawkmoths, and dragonflies. Because of their small size, many miniature insects fly at a Reynolds number ($\mathrm{Re}$) on the order of 10 or less. At such a low $\mathrm{Re}$, the viscous effect of the air is substantial: A miniature insect moves through the air as a bumblebee would move through mineral oil. The great importance of viscosity for miniature insects means that their flight relies on physical mechanisms that are different than those exploited by large insects. These differences range from the nature of the wing stroke to the structure of the wings, with some insects even using porous (bristled) wings to fly. Over the past decade, much work has been done in the study of the mechanics of flight in miniature insects: novel flapping modes have been discovered and new mechanisms of aerodynamic-force generation have been revealed; progress has also been made on fluid-mechanics-related flight problems such as flight power requirements and flight dynamic stability. This Colloquium reviews these developments and discusses potential future directions.

中文翻译：

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座谈会：微型昆虫飞行

许多现有的有翅昆虫物种都非常小（翅$\text{长度}\approx 0.3–4\mathrm{毫米}$）；它们被称为微型昆虫。然而，直到最近，我们关于昆虫飞行机制的大部分知识都来自对相对较大的昆虫的研究，例如苍蝇、蜜蜂、天蛾和蜻蜓。由于体型小，许多微型昆虫以雷诺数飞行（$\mathrm{关于}$) 的数量级为 10 或更少。在这么低的情况下$\mathrm{关于}$，空气的粘性效应是巨大的：微型昆虫在空气中移动，就像大黄蜂在矿物油中移动一样。粘度对于小型昆虫非常重要，这意味着它们的飞行依赖于与大型昆虫所利用的物理机制不同的物理机制。这些差异包括从翅膀行程的性质到翅膀的结构，有些昆虫甚至使用多孔（有鬃毛）的翅膀来飞行。在过去的十年中，人们在微型昆虫的飞行力学研究方面做了很多工作：发现了新的扑动模式并揭示了产生气动力的新机制；在飞行动力要求、飞行动态稳定性等流体力学相关飞行问题上也取得了进展。本次研讨会回顾了这些发展并讨论了潜在的未来方向。