Collaborative Research: Causes and Consequences of Intraspecific Variation in Developmental Plasticity: Growth, Size and Instar Number in Manduca Sexta

Understanding how developmental processes evolve is a fundamental challenge for evolutionary biology. The Tobacco Hornworm, Manduca sexta, a major agricultural pest of tobacco and tomato in the Southeast US, is an important model system for understanding the growth, development and metamorphosis of insects, and laboratory colonies of M. sexta have been maintained for over 40 years. Recent studies have revealed surprising genetic variation and developmental plasticity in the number of larval stages (instars) in field populations of M. sexta. The proposed research will study the nutritional and developmental mechanisms that cause variation in instar number, and document the consequences of instar number for caterpillar growth and feeding, adult size, and female fecundity (number of eggs). This project will document how variation in development is maintained within insect populations in nature, and how developmental variation influences feeding, growth and fitness of this important agricultural pest.

This project will include the training of undergraduate and graduate students in Biology at the University of North Carolina and Duke University as well training high school teachers.