A fruit fly covered in the catching threads of an uloborus plumipes spider.
Hana Adamova
In contrast to most other spiders, cribellate spiders do not use glue on their threads but can turn their silk into complex structures by linking up to 40,000 nanofibres. The thread is thereby completely dry, yet still adhesive. As part of the “Cribellate Spiders” project, researchers at the RWTH Aachen University, Johannes Kepler University Linz and Johannes Gutenberg University Mainz have now investigated this special ability to process nanofibres and found that these spiders’ silk adheres to insects in a way that was unknown until now.
The individual nanofibres cannot be detected, but rather are encased in a fluid as soon as the insect touches the web according to the researchers in their study. Analysis of this fluid has shown that the same chemicals are present there as in the wax that insects use on their chitinous exoskeleton to protect themselves from evaporation. When an insect touches the web, the woolly nanofibres therefore soak up the waxy chemicals of the chitinous exoskeleton, and thereby turn the lightweight silk into a solid structure. “The result of this adhesion is similar to the principle of a fibre-reinforced plastic. The prey strengthens its own jail”, explains Anna-Christin Joel, head of the project. These research results should also once again contribute to the biomimetic transfer of solutions applied by animals to technical processes.