Collective Olfactory Communication in Honeybee Swarms

信息素是自然界中普遍存在的挥发性通信信号，但其信息交换的范围和噪声容忍度受到这些信号的时空衰减的限制。研究人员将以蜜蜂为模式生物，研究蜂群通过追踪蜂王的信息素来定位蜂王的通信网络。具体地说，离蜂王很远的蜜蜂如何找到她？蜜蜂通过位于腹部的信息素腺体传播关于蜂王位置的信息。重要的是，蜜蜂不仅被动地散发这些信息素，而且还主动地扇动翅膀，从而沿着它们的前后轴吸入空气。研究人员将研究局部气流，PI假设它在信息素的扩散中产生方向偏差，以确保信号到达群的其余部分。由于蜜蜂在特定的空间分布中排列，其中个体之间存在特征距离，并且个体广播信号的特征方向，研究人员将研究（1）随着信息素传播距离的增加，这个动态网络如何随着时间的推移招募新的广播蜜蜂，这是个体大小的数量级;以及（2）群如何克服诸如固体物体以及湍流气流和相反的化学信号的局部障碍。我们的世界充满了生物，它们为了生存和繁殖而经常相互交换信息。理解这些通信信号不仅是生物学上的问题，也是物理学上的问题--考虑到交换信息的能量成本、压缩和可检测性。由于信号产生的能量成本驱使蜜蜂在最小信号设计和最大信噪比方面推动包络，这些迷人的通信策略可以揭示信号设计和信号处理的新优化。利用这些自然的解决方案-经过进化，选择和改进的磨练-我们不仅可以更深入地了解集体动物行为，而且还可以利用这种理解在群体机器人和分布式通信领域创建生物启发的系统设计，更不用说在农业上了。蜂群拥有令人印象深刻的技能，当涉及到操纵大长度时，缩放物理场，如机械应变和流动介导的温度。但要成为一个连贯的蜂群，蜜蜂首先必须通过跟踪在时间和空间中迅速衰减的信息素来定位它们的女王。与传统的各向同性化学信号（如在早期胚胎发育和阿米巴聚集中所见）不同，蜜蜂使用一种新的手段来引导它们的通信信号-气流。在这个复杂的系统中，个体（昆虫）可以感知它们的微环境，并以促进生存的方式做出反应;通常，这种反应会改变个体所处的宏观环境，从而在个体，群体和环境之间建立永久的耦合。当与定量分析和计算相结合时，研究人员将整合对环境线索（信息素浓度和气流）的感知，并将其转换为行为输出，使蜂群保持一致。因此，这项工作扩展了传统的集体行为观点，通过stigmergy（其中生物体对局部线索的反应很少或没有长期影响）建立由物理学介导的长期相互作用。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估而被认为值得支持。

Pheromones are a prevalent volatile communication signal in nature, but their range and noise tolerance of information exchange are limited by the spatiotemporal decay of these signals. Using honeybees as a model organism, the researchers will study the communication network of honeybee swarms that locate their queen by tracking her pheromones. Specifically, how can honeybees that are far away from the queen locate her? Bees disperse information about the queen's location via a pheromone gland located on their abdomen. Importantly, bees not only passively diffuse these pheromones but also actively fan their wings, which draws air along their anteroposterior axis. The researchers will study the localized airflow, which the PI hypothesized that it creates a directional bias in the diffusion of the pheromones to ensure the signal reaches the rest of the swarm. As bees arrange in a specific spatial distribution where there is a characteristic distance between individuals and a characteristic direction in which individuals broadcast the signal, the researchers will study (1) how this dynamic network recruits new broadcasting bees over time as the pheromones traveled a distance which is orders of magnitude the size of an individual; and (2) how the swarm overcomes local obstacles such as solid objects as well as turbulent airflow and opposing chemical signals. Our world is full of living creatures who routinely exchange information with each other in order to survive and reproduce. Understanding these communication signals is not just a problem in biology, but also one in physics - given the energetic cost, compression, and detectability of the exchanged information. Since the energetic cost of signal production drives bees to push the envelope in terms of minimal signal design and maximal signal to noise ratios, these fascinating communication strategies could reveal new optimalities in signal design and signal processing. Harnessing these natural solutions - honed by eons of evolution, selection, and refinement - we can not only more deeply understand collective animal behavior, but also leverage that understanding to create bio-inspired system designs in the fields of swarm robotics and distributed communication, not to mention in agriculture.Honeybee swarms hold an impressive skill-set when it comes to manipulating large length-scale physical fields such as mechanical strains and flow-mediated temperatures. But to become a coherent swarm in the first place, honeybees must locate their queen by tracking her pheromones that decay rapidly in time and space. Unlike the traditional isotropic chemical signaling (as seen in early embryonic development and aggregation of amoebae), bees use a new artifice to direct their communication signal - airflow. In this complex system, the individual building blocks (an insect) can sense their micro-environment and respond in a way that promotes survival; typically, the response changes the macro-environment the individual is embedded in, thus creating a perpetual coupling between the individuals, the group and the environment. When combined with quantitative analysis and computations, the researchers will integrate the sensing of the environmental cues (pheromone concentration and airflow) and convert them to behavioral outputs that allow the swarm to remain coherent. Hence, this work expands the traditional view of collective behavior via stigmergy (wherein organisms respond to local cues with little or no long-range effects) to establish long-range interactions mediated by physics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.