Dense white trichome production by plants as possible mimicry of arthropod silk or fungal hyphae that deter herbivory

Some spiders are well-known to mimic flowers or other plant surfaces in order to be cryptic to both their prey and their predators. We propose that dense, thread-like white trichomes of some plants from Estonia, Greece, Israel and Japan visually mimic spider webs, lepidopteran and spider-mite web nests and plant-pathogenic fungi, and that it may result in reduced herbivory, since various herbivores avoid spider- or other arthropod webs to circumvent predation or toxic attacks, or refrain from colonizing plants that have already been occupied by other herbivores and pathogens. Spiders and other web-forming arthropods are also the prey of certain vertebrate predators and wasps, and therefore such predators may be attracted to these web-like plant structures and prey on the invertebrate herbivores occupying them. We do not dismiss the possibility that these web-like structures may also have other defensive or physiological functions or that they are not classic mimics but rather exploit the herbivore׳s perceptual state concerning the avoidance of potentially risky objects.