Adults can range from 10 to 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. 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.
Adults and nymphs feed on milkweed plant juices, seeds and occasionally on other plant juices. After feeding on milkweed plant or seeds, the insects accumulate toxic glycosides in their bodies. This, combined with warning orange color, protects them against predators (aposematism).