Alkaloid ("Agonopterix alstroemeriana)." This moth feeds on its highly toxic and alkaloid-rich host plant poison hemlock ("Conium maculatum") during its larval stage. "A. asltroemeriana" may benefit twofold from the toxicity of the naturally-occurring alkaloids, both through the unpalatability of the species to predators and through the ability of "A. alstroemeriana" to recognize "Conium maculatum" as the correct location for oviposition. Medical use of alkaloid-containing plants has a long history, and, thus, when the first alkaloids were isolated in the 19th century, they immediately found application in clinical practice. Many alkaloids are still used in medicine, usually in the form of salts,
Poison dart frog by the relatively large size and high levels of toxicity of its members. Most species of poison dart frogs are small, sometimes less than in adult length, although a few grow up to in length. They weigh 1 oz. on average. Most poison dart frogs are brightly colored, displaying aposematic patterns to warn potential predators. Their bright coloration is associated with their toxicity and levels of alkaloids. For example, frogs of the genus "Dendrobates" have high levels of alkaloids, whereas "Colostethus" species are cryptically colored and are not toxic. Poison dart frogs are an example of an aposematic organism. Their