The Design, Diversity, and Performance of Viscous Capture Threads Produce by Araneoid Orb-weaving Spiders

这个项目研究了在4000多种蜘蛛生产的圆网中发现的粘性捕获线的设计和功能。这些粘性的线是由悬浮在弹性纤维上的小粘性液滴形成的。研究确定：1.什么粘附力有助于液滴粘性；2.这些力是如何被纤维以阻止裂纹扩展的方式吸收的；3.液滴的大小、可塑性和间距如何优化线粘性；4.具有不同液滴轮廓的线对不同质地的昆虫表面的保持能力；以及5.具有不同捕获线特性的圆网保持昆虫的能力。这是通过以下方式完成的：1.测量具有不同液滴特征的线如何粘在不同宽度和纹理的表面上，2.开发描述线性能的模型，3.对许多蜘蛛物种产生的线和球网的特征进行调查和比较分析，以及4.测量昆虫被具有不同捕获线特征的球网停留的时间。这些互补的方法解释了粘性丝线是如何作为一个集成的粘接系统运行的，该粘接系统利用离散单元的复合粘合并抵抗裂缝比例分配，这是天然和制造粘接系统面临的一系列严重挑战。这些研究的原理和见解将帮助材料科学家开发新的产品和应用。这些研究还显示了捕获线设计如何通过球状编织蜘蛛增强猎物捕获，以及它如何促进猎物专门化。这些都是重要的问题，因为蜘蛛是自然生态系统中的主要捕食者，作为生物控制昆虫的媒介正受到越来越多的关注。制定了教育练习，让小学生和高中生参与实地和实验室研究，使用显微镜、数码相机、计算机程序和简单的自制仪器来收集和分析蜘蛛网及其线的特征数据。

This project examines the design and function of viscous capture threads that are found in orb-webs produced by over 4,000 species of spiders. These sticky threads are formed of small adhesive droplets suspended on elastic fibers. Studies determine: 1. What adhesive forces contribute to droplet stickiness, 2. How these forces are recruited by fibers in a manner that resists crack propagation, 3. How droplet size, plasticity, and spacing optimize thread adhesion, 4. How well threads with different droplet profiles hold insect surfaces of different textures, and 5. How well orb-webs with different capture thread characteristics retain insects. This is done by: 1. Measuring how threads that have different droplet features stick to surfaces of different widths and textures, 2. Developing models that describe thread performance, 3. Conducting a survey and comparative analysis of the features of threads and orb-webs produced by many spider species, and 4. Measuring the time that insects are retained by orb-webs that have different capture thread features. These complementary approaches explain how viscous thread operates as an integrated adhesive system that recruits the compound adhesion of discrete units and resists crack prorogation, a set of serious challenges to both natural and manufactured adhesive systems. The principles and insights from these studies will help materials scientists develop new products and applications. These studies also show how capture thread design enhances prey capture by orb-weaving spiders and how it may facilitate prey specialization. These are important issues, as spiders are key predators in natural ecosystems and are receiving increasing attention as agents of biological insect control. Educational exercises are developed that involve grade school and high school students in field and laboratory studies that use microscopes, digital cameras, computer program, and simple, homemade instruments to collect and analyze data on the features of spider orb-webs and their threads.