The Characterization of Embiopteran Silk and Its Interactions with Water*

Embioptera (webspinners) are insects that produce silk in glands housed in their forelegs (basitarsomeres). Embioptera use this silk for shelter and protection from predators. Their silk is the finest of all known animal silks, with fibers on the order of 0.05-0.1 μm in diameter. In comparison, spider and silkworm silks have diameters of roughly 1-4 μm and 5-10 μm respectively. Through the use of scanning electron microscopy (SEM), we quantified the silk diameters of multiple species of embioptera and discovered unique silk structures that these insects produce. In the field, water appears to interact differently with silk from different species. We have studied how water droplets change the structure, morphology, and chemistry of the silk at the macroscopic scale through contact angle and tilt angle measurements and at the nano scale using SEM. These studies have allowed us to better understand the characteristics of Embioptera silk.