Defense against predators is critical, and moths have evolved an impressive array of anti-predator strategies to defend themselves. Camouflage in particular is a cost-effective way to escape a predator’s attention and has been widely studied, albeit mainly in the visual domain. Most moths are, however, night-active and therefore mainly need to defend themselves against bats hunting by sound, specifically through echolocation. To escape detection, moths may consequently have evolved scales on body and wings for acoustic camouflage, as these microstructures can in some species absorb ultrasound.
Here, our central aim is to identify form-function relationships of scales and scale assemblages producing acoustic camouflage.
To achieve our aim, we will first carry out a survey of the diversity in acoustic camouflage properties of a large set of species. Focusing on a subset of interesting species, we will then measure morphological properties of different classes of body and wing scales and model their sound absorptive or scattering capacities. Furthermore, we will determine how acoustic properties of these scale classes may trade off with other functions, in particular thermal regulation. Finally, we will test our form-function hypotheses via biomimicry, producing both analogues that directly mimic and extend the variation in scale morphology.
Our research plan will provide critical insight into the evolution and application of moth scales as a specialized antipredator strategy and its outcome may enable us to extend acoustic camouflage beyond what is found in nature,thereby improve functional performances. This will not only allow us to rigorously test our proposed form-function relationships but also potentially enable development of new thin sound-dampening materials with Air Force applications.