Umbonia crassicornis is a common and widespread member of the family Membracidae, and one of numerous species colloquially referred to as thorn bugs. The body length of the adult is approximately 10 millimetres (0.39 in). This is a variable species as to size, color and structure, particularly the pronotal horn of males (which is more angled posteriorly than the females' and often somewhat expanded apically). This tall, essentially perpendicular thorn-like pronotum discourages birds and other predators from eating it, if only by mistakenly confusing it with a thorn. Typically, the adult is green or yellow with reddish lines and brownish markings. The range of this species is from Northern South America all the way to Mexico and Florida. Three other species in this genus occur elsewhere in the United States. Its preferred hosts are ornamental and fruit trees of subtropical regions.