Exploring silk dynamics data.csv
Description
The study examines how silk produced by detritivores living in dry regions might differ from that of tropical arboreal webspinners (Embioptera). The detritivores are Haploembia tarsalis and Oligotoma nigra. The tropical species are Antipaluria urichi and Pararhagadochir trinitatis. Webspinners rely on silk for protection, including from rain and flooding. They spin the finest silks known in nature. The amino acid compositions vary from one species to the next and might impact how the silk interacts with water. Fiber diameter also varies, whereby the detritivores spin finer silks (approximately 48 nm diameter) than the arboreals (72 - 122 nm). Water-silk interactions are known for Embioptera, as the fibers transform to a film when wetted. In either case, the silk protects the insects within the silk galleries from water. Silk was imaged by SEM and quantified as density based on pixels using ImageJ Fiji. After exposure to water, the silk surface transforms to a film; the film density was quantified the same way as were the dry fibers. Disappearance rates of the water droplets placed on silk was recorded and revealed that the one species (Oligotoma nigra) with hydrophobic silk amino acids showed the slowest transformation rate when exposed to water. The two arboreal species showed higher density of spun silk fibers and of the resulting silk films after wetting compared to the detritivores. Possible adaptive value is that the tropical species rely more on a thick silk coating as protection from natural enemies and from heavy rainfall. Embioptera silk is not well studied; further work is needed to elucidate the variability as demonstrated by this preliminary investigation of silk diversity.
Files
Steps to reproduce
Scanning electron microscopy, Zeta-20 3D Profiler, ImageJ Fiji, Transformation of silk fibers to film (timing, density of fibers and film, disappearance rate of water droplets on silk)