Orb-weaving spiders are known to create stabilimenta – silk situated at particular
locations of the web. While anecdotal reports and popular media have long suggested
that some spiders arrange debris in their webs to resemble a larger spider, this behavior
has not been formally documented in the scientific literature. Here, we provide the
first scientific record of this unique behavior in two orb-weaving spiders (Cyclosa
spp., Araneidae) from the tropical forests of Peru and the Philippines. We report
that these spiders construct stabilimenta composed of detritus and silk, arranging
the debris in the web into a shape that visually resembles the silhouette of a larger
spider. This structure may serve as a “decoy” that serves an anti-predator function
of misdirecting or repelling the attacks of some predators.
