The biophysics of aerial electroreception in arthropods

我们最近发现，大黄蜂可以探测和学习当它们接近一朵花时产生的电场。一个微弱的电场确实建立了熊蜂，像其他飞行的昆虫一样，往往是带正电的，而花朵往往有过量的负电荷-电子。利用教蜜蜂识别具有糖奖励的花朵的实验，可以证明蜜蜂可以仅仅根据花朵的电场来记住哪种花朵含有糖奖励。新的证据表明，蜘蛛也可以使用电场;这一次飞！我们确实可以在实验室和野外展示，蜘蛛通过在空中投掷几股最细的丝来完成气球飞行。当蜘蛛踮起脚尖站在高高的草或叶子上时，它们的丝帆会受到大气中静电的提升力。有趣的是，我们可以证明气球在完全没有风的情况下也会发生，解决了查尔斯达尔文在观察成千上万只小蜘蛛从他的小猎犬号的船尾降落时问自己的一个问题。我们想知道细小的毛发是否能对电力作出反应。我们首先想象蜜蜂可能会经历一些类似于我们过去接近旧电视机时的毛骨悚然的感觉。对于蜜蜂和蜘蛛，我们测量了它们暴露在电场中的微小毛发运动，就像在自然界中发现的那样，使用精细的激光束。因此，我们发现蜜蜂和蜘蛛有专门的传感器-细毛-来检测弱电场。但是其他昆虫也能探测到电场吗？为什么？我们选择研究一组重要的昆虫-甲虫，因为它们在全球生态学中起着至关重要的作用，并允许我们调查小昆虫可能使用电场的其他原因。我们选择了瓢虫幼虫和码头甲虫，因为它们的背上有明显的一排排细毛，其功能目前尚不清楚。我们假设，带负电荷的叶栖昆虫使用这些毛发来电检测带正电荷的接近飞行的捕食者和寄生虫，如黄蜂和苍蝇。在野外，我们观察到瓢虫和码头甲虫幼虫对接近它们的电荷的存在做出反应。我们注意到，瓢虫幼虫有组织良好的毛簇行，其功能是未知的。在这里，我们试图建立是否检测电场也属于捕食者或猎物检测，功能超出了授粉，这是相关的许多昆虫物种，在生态系统和农业中发挥重要作用。弱电场是普遍存在于自然环境中，但显然，没有被人类感觉到。我们的工作还旨在提高我们的意识，更好地理解电力环境和我们的电力生态。因此，我们的研究项目有助于开发新的方法来测量和了解人类，动物和植物的感官生态学的这种潜在重要组成部分的存在。我们将收集数据并制作视觉媒体，使这一迄今为止难以捉摸的自然世界的一部分变得可见。我们将采用我们新颖的电学测量和可视化技术，学习小昆虫探测弱电场的方式。使用3D打印技术，我们将建模，设计和构建由可充电塑料制成的昆虫状毛发结构。这种生物启发的方法将有助于这项研究的长期影响。因此，我们的研究还将提供科学信息，使有关人造电场对人类，环境和支持重要生态网络和服务的生物体可能产生的影响的更一般性问题成为可能。

We recently discovered that bumblebees can detect and learn about the electric fields that arise when they approach a flower. A weak electric field indeed builds up as bumblebees, like other flying insects, tend to be positively charged, and flowers tend to have an excess of negative charges - electrons. Using experiments that teach bee to recognize flowers with sugar rewards, it was possible to show that bee can memorise which flower contains sugar rewards on the sole basis of the flower's electric field. New evidence shows that spiders can also use electric fields; this time to fly! We could indeed show in the lab and in the field, that spiders perform ballooning flights by casting in the air several strands of their finest silk. As the spider stands on its tiptoes on top a tall grass or leaf, their silk sail experiences an uplifting force from the electrostatics in the atmosphere. Interestingly, we could show that ballooning takes also place in the total absence of wind, solving a question that Charles Darwin asked himself as he observed thousands of tiny spiders alighting the riggings of his ship, the Beagle.Bumblebees are quite furry, a coat deemed useful to staying warm and collecting pollen. We wondered whether fine hairs can react to electric forces. We first imagined that bees may experience something similar to the hair-raising sensation we used to have when approaching an old television set. For bees and spiders, we measured the tiny hair movements as they are exposed to electric fields like those found in nature, using a fine beam of laser light. We thus discovered that bees and spiders have dedicated sensors -fine hairs- to detect weak electric fields. But do other insects detect electric fields, and why? We have chosen to study an important group of insects - beetles because they play crucial roles in global ecology and allow us to investigate other reasons why small insect may use electric fields. We have chosen ladybird larvae and dock beetles because they have distinct rows of fine hairs on their backs, the function of which is currently unknown. We hypothesise that negatively charged leaf dwelling insects use these hairs to electrically detect positively charged approaching flying predators and parasitoids, such as wasps and flies. In the field, we have observed that ladybird and dock beetle larvae react to the presence of an electric charge approaching them. We note that ladybird larvae have well-organized rows of hair tufts, the function of which is unknown. Here, we seek to establish whether the detection of electric field also pertains to predator or prey detection, functions that go beyond that of pollination and that is relevant to many insect species that play important roles in ecosystems and agriculture.Weak electric fields are pervasive in the natural environment, but apparently, are not sensed by humans. Our work also aims at increasing our awareness, shaping a better understanding of the electric environment, our electric ecology. Our research project therefore serves to developing new ways to measure and understand the existence of this potentially important component of the sensory ecology of humans, animals and plants. We will be collecting data and producing visual media that will make visible this thus far elusive part of the natural world. We will employ our novel electrical measurement and visualisation techniques, learning from the way small insects detect weak electric fields. Using 3D printing techniques, we will model, design and construct insect-like hair structures made of electrically chargeable plastics. This bio-inspired approach will contribute to the long-term impacts of this research. As such, our research will also provide scientific information enabling more general questions about the possible impacts of man-made electric fields on humans, the environment and the organisms supporting important ecological networks and services.