Meeting Abstract
Tobacco employs the chemical nicotine as a method to deter defoliation by herbivores. Some species, such as the Tobacco Hornworm, Manduca sexta, tolerates the noxious chemical and specializes upon these toxic plants. This caterpillar is a significant crop pest and is the subject of constant eradication efforts by farmers. While we know that M. sexta mostly passes the nicotine in feces and does not incorporate much (if any) of the noxious chemical into its own tissues, the effects of increased nicotine concentrations on its physiology and performance is generally unknown. In our study, we report differences in growth rate, digestive efficiency, metabolic rate, and performance of M. sexta being fed different concentrations of nicotine in commercially-available caterpillar food. Our findings suggest that the tobacco plant can negatively impact hornworm physiology by producing more nicotine. Future complementary field studies may reveal the extent that tobacco plant can upregulate nicotine production and what levels are effective in situ. This laboratory investigation provides a better understanding of M. sexta physiology and its relationship with Nicotiana tabacum.
