The bright orange-red coloration of these immature large milkweed bugs (Oncopeltus fasciatus) is a warning to predators that they taste bad. Like monarch butterflies, they concentrate foul-tasting compounds from the narrow-leaf milkweed (Asclepias fascicularis) in their bodies.

Following several instars (molts), the nymph is transformed into the adult insect.

The photograph is from a run at Sage Ranch on July 23, 2007.