Milkweed Leaf Beetle - Labidomera clivicollis

Milkweed contains poisonous compounds called cardiac glycosides. Monarchs (and some other insects) that feed on milkweed can tolerate and store these chemicals, thus making them poisonous to predators. Monarchs, in addition to other milkweed-eating insects, have black and orange warning colors (aposematic) to warn predators that they taste gross.

Birds that eat an insect containing cardiac glycosides will basically end up with a really bad stomachache. Once a bird (or other predator) has ingested and gotten sick from eating a black and orange insect, such as a monarch, it learns to avoid any and all insects with similar coloration.

Milkweed leaf beetles eat milkweed and have black and orange coloring, BUT they do not absorb the cardiac glycosides from the milkweed like a monarch would. So, they are not actually poisonous to predators. However, insect-eating birds don’t know this, and the beetles successfully deter predation simply because of their coloration and association with milkweed.

Habitat: Swamp milkweed