Insect herbivory of black henbane (Hyoscyamus niger): a research proposal and preliminary assessment from Colorado, Montana and Wyoming

Biological invasions provide ideal systems to study the evolutionary processes associated with the colonization of a new area by an exotic species. There is much support for the idea that release from native enemies enables invaders to dominate communities. A corollary to this, focused on invasive plants, is the evolution of increased competitive ability hypothesis (EICA), which predicts that plants released from native specialist enemies evolve to allocate resources away from resistance and toward development and reproduction. An excellent study system to address these issues is provided by Hyoscyamus niger, a solanaceous weed native to Eurasia and invasive in North America. This state-listed noxious weed is chemically complex and toxic to both livestock and humans, yet there is surprisingly little information on its ecology or interactions with insect herbivores. To begin to fill this gap in knowledge, I surveyed for insect herbivores and documented rates of herbivory on populations from the invaded range, including Colorado, Montana, and Wyoming. In addition to presenting these data I will discuss research plans to examine the potential for a tradeoff between resistance and tolerance to insect herbivory and its role in biological invasions. I hypothesize that increased tolerance to herbivory may facilitate the successful establishment and spread of invasive plants.