METHODS Biological Materials The herbivore we used in this experiment was the Manduca sexta; also known as the tobacco hornworm. The tobacco hornworm was a chosen for this herbivory experiment because they are easy to obtain and have predicable growing patterns; this way, we could easily measure their growth during our experiment. Another reason we used Tobacco hornworms was because they also have the ability to detoxify the nicotine (at an energetic cost) from tobacco plants. Tobacco hornworms are specialist herbivores, meaning they primarily feed on one family of plants. For tobacco hornworms, their primary family of plants is tobacco family, which is why they have evolved to overcome the chemical defence mechanism of the tobacco family. Because of this ability, hornworms are a major agricultural pest that can rapidly defoliate fields of tobacco, tomatoes, and related plants if they're undetected for too long. These tobacco hornworms are found in Central America, the United States, and in the southern regions of Canada. The hornworms used in our experiment is obtained during their egg state from Carolina Biology Supply Company. To minimize cofounding variables, all the hornworms were brought up with the same growth conditions. They were maintained at 22+2?, with 18 hours of light/day, and reared with wheat germ growth medium (also from Carolina Biology Supply Company), until the majority of them were in their third instar larval stage (three weeks). Plants The plants that we used in this study were the Nicotiana alata (Jasmine tobacco plant) and the Nicotiana rustica (Aztec tobacco plant). The plants were both approximately 4 weeks old at the start of our experiment.We chose the Jasmine tobacco plant and Aztec tobacco plant not only because of our research question, but also because we know that the tobacco hornworms will feed on both tobacco plants from the Solanaceae family, (hornworms mainly feed on tobacco plants). Since tobacco hornworms have evolved the ability to detoxify nicotine (at an energetic cost), and we know that the two plants produce different levels of nicotine, we decided to base our research question on this concept; to measure the energetic cost it has on the hornworm when eating the Jasmine tobacco plant compared to the Aztec tobacco plant. Both plants were obtained as seeds from different suppliers. The Aztec tobacco plant seeds were from Elana's Organic Garden (Lowbanks, ON), and the Jasmine tobacco plant seeds were from West Coast Seeds (Vancouver, BC). The seeds were planted in Pro-Mix potting soil, proximately 4 weeks prior to the beginning of our experiment. To minimize cofounding variables, both of the plants were grown in the same conditions. The plants were grown at 22+2?, with 18 hours of light/day, with watering when needed. 20-20-20 fertilizer was applied twice over that period of time. During the experiment, to further minimize cofounding variables, clear plastic cups were used to cover the plant so we can limit the transmission of airborne plant defense signals. All the plants were watered at the same time so the plants can grow