Spilostethus is a genus of insects belonging to the family Lygaeidae. They are commonly known as the "cotton stainers" due to their ability to feed on and stain cotton plants. These insects are typically small in size, ranging from 5 to 10 millimeters in length, and have a distinctive coloration with bright red or orange markings on a black or dark brown background. They are found in various regions around the world and are considered agricultural pests due to their feeding habits.