What are the small, reddish-orange and black bugs on my milkweed plants?
This insect is a milkweed bug (Oncopeltus fasciatus). The young stage (nymphs) are smaller and all reddish-orange, while the older stage (adults) have black markings as well. Milkweed bugs feed on the seeds and suck the juices from the new growth. Milkweed bugs have few predators, as they concentrate in their bodies the bad tasting toxins found in the sap of milkweed plants. The bugs’ bright, reddish-orange coloration advertises the fact that they taste bad to other insects and critters that might want to eat them. Inexperienced birds that taste their first milkweed bug are unlikely to try to eat anything orange and black ever again! Some insects that do not taste bad use similar color patterns to fool birds. These are known as mimics. To control the milkweed bugs, you can simply pick them off and squash them. Using a pesticide to control them is not recommended, as milkweed is often a host plant for Monarch butterfly larvae.
