Abstract
Nutrition has far‐reaching effects on both the ecology and evolution of species. A substantial body of work has examined the role of host plant quality on insect herbivores, with a particular focus on specialist–generalist dynamics, the interaction of growth and other physiological attributes on fitness and tritrophic effects. Measures of plant quality usually involve one or two axes of nutritional space: typically secondary metabolites or elemental proxies (N and C) of protein and carbohydrates, respectively.Here, we describe the nutrient space of seven host plants of the specialist insect herbivore, Manduca sexta, using an approach that measures physiologically relevant sources of nutrition, soluble protein and digestible carbohydrates. We show that plant species differ markedly in their nutrient content, offering developing insect herbivores a range of available nutrient spaces that also depend on the age of the leaves being consumed.The majority of host‐plant species produce diets that are suboptimal to the herbivore, likely resulting in varying levels of compensatory feeding for M. sexta to reach target levels of protein to ensure successful growth and development. Low‐quality diets can also impact immune function leading to complex patterns of optimization of plant resources that maximizes both growth and the ability to defend from parasitoids and pathogens. This study is the first to quantify the nutrient space of a suite of host plants used by an insect herbivore using physiologically relevant measures of nutrition.
Highlights
Nutrition shapes broad patterns in ecology and evolution and is par‐ ticularly important in impacting the interactions between plants and insect herbivores
We describe the nutrient space of seven host plants of the specialist insect herbivore, Manduca sexta, using an approach that measures physiologically rel‐ evant sources of nutrition, soluble protein and digestible carbohydrates
We show that plant species differ markedly in their nutrient content, offering developing insect herbivores a range of available nutrient spaces that depend on the age of the leaves being consumed
Summary
Nutrition shapes broad patterns in ecology and evolution and is par‐ ticularly important in impacting the interactions between plants and insect herbivores. Elemental analysis of plants has long been the standard for quan‐ tifying protein and carbohydrate components with nitrogen acting as a proxy for protein and carbon acting as a proxy for carbohydrates (Berner, Blanckenhorn, & Körner, 2005; Deans et al, 2016; Telang, Booton, Chapman, & Wheeler, 2001) Though this approach has generated useful research outcomes (Joern et al, 2012), researchers have recently made the case for using more direct measurements of soluble protein and digestible carbohydrates (Deans et al, 2016). We take an insect‐centric approach and use methods outlined by recent work (Deans et al, 2016) to examine soluble protein and digestible carbohydrates in a suite of host plants used by a specialist insect herbivore: Manduca sexta (Sphingidae). The shelf‐stable samples were preground using a ceramic mortar and pestle and placed into a Mills grinder that was set to run on the highest level of grinding for 30 s
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
