Some caterpillars use toxins from their host plants to their advantage. They store the toxins in their bodies and use them to protect themselves from predators.
One example is the monarch caterpillar and its host plant, milkweed. Milkweed contains cardiac glycoside, a toxin that disrupts molecular pumps that control the proper flow of ions in and out of cells. This toxin can seriously affect vertebrate predators, including birds, and often causes them to vomit which stops predators from eating Monarch caterpillars.
Cardiac glycoside stays in the caterpillar and the adult butterfly and gives protection from birds and other predators.
By Karen Bowen. Karen is a member of the Yuma Orchid & African Violet Society, a master gardener, and a Pacific Region Butterfly Chairman.
Be sure to check out this blog Texas Mountain Laurel for more information about Mountain Laurel.