What flavorful toast topping could double as an insecticide? If you guessed cinnamon, you guessed right.
The essential oil from the Taiwanese cinnamon tree (Cinnamomum osmophloeum) was found to be highly toxic to fire ants, noxious pests in the southeastern United States in recent years. Researchers placed fire ants in small containers (some open and some covered) and sprayed them with an alcohol-based solution containing varying concentrations of cinnamon oil. All of the ants in the covered containers sprayed with the 1 or 2 percent solution died in just over an hour. Those in uncovered containers were a bit luckier—about 60 percent of them died after three hours. However, when one of the major chemical constituents of cinnamon oil was isolated and sprayed on the ants at a 2 percent concentration, 100 percent of the ants died within 90 minutes—even in the open containers.
For more information, see Bioresource Technology 99(4) 889-893, March 2008.
Robin Siktberg is horticulturist and editor for the Herb Society of America. Steven Foster is an author, photographer and consultant specializing in medicinal plants.