Polistes dominula, a species of paper wasp, a type of wasp that gathers fibers from dead wood and plant stems, which they mix with saliva, and use to construct water-resistant nests that appear to be made of gray or brown papery material. The nests of most true paper wasps are characterized by having open combs with cells for brood rearing, and a petiole, or constricted stalk, that anchors the nest.Photo credit: Joaquim Alves Gaspar