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

该项目研究了 4,000 多种蜘蛛产生的球网中发现的粘性捕获线的设计和功能。 这些粘性线由悬浮在弹性纤维上的小粘合剂液滴形成。 研究确定： 1. 哪些粘附力有助于液滴粘性， 2. 纤维如何以抵抗裂纹扩展的方式吸收这些力， 3. 液滴大小、可塑性和间距如何优化线粘附， 4. 具有不同液滴轮廓的线如何更好地保持不同纹理的昆虫表面，以及 5. 具有不同捕获线特征的球网保留昆虫的效果如何。 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附到不同宽度和纹理的表面， 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. 测量具有不同捕获线特征的球网保留昆虫的时间。 这些互补的方法解释了粘性线如何作为一个集成的粘合剂系统发挥作用，该系统吸收离散单元的复合粘合力并抵抗裂纹扩展，这是对天然和人造粘合剂系统的一系列严峻挑战。 这些研究的原理和见解将帮助材料科学家开发新产品和应用。 这些研究还表明，捕获线设计如何增强球织蜘蛛的猎物捕获，以及它如何促进猎物专业化。 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，并且作为生物昆虫控制剂而受到越来越多的关注。 开发了教育练习，让小学生和高中生参与现场和实验室研究，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有关蜘蛛球网及其丝的特征的数据。

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.