Adults can range from 10–18 mm in length and have a red/orange and black X-shaped pattern on their wings underneath the triangle that is typical to hemipterans. This feature makes the bug easily seen, acting as a aposematic warning to predators of distastefulness. O. fasciatus exhibits müllerian mimicry and is noxious to predators. The ventral side of the fourth abdominal segment bears a black band in the male and two black spots in the female. Juveniles are born mostly red with black antennae and a few black spots, throughout growth the black spots are developed as well as wing pads. Eggs of this insect are bright orange and easily detectable.
These little guys won't kill your milkweed or harm monarch caterpillars/eggs, but too many could reduce seed harvest because they feed on milkweed seeds.
removing eggs will reduce the number of milkweed bugs if seed production is your main objective.
Please don't use chemicals!