Brenthia monolychna is a species of moth of the Choreutidae family. It is found in Costa Rica. Adults mimic jumping spiders, one of their predators. In a recently conducted experiment, Brenthia hexaselena and Brenthia monolychna had higher survival rates than other similarly sized moths in the presence of jumping spiders and jumping spiders responded to Brenthia with territorial displays, indicating that the species were sometimes mistaken for jumping spiders, and not recognized as prey.