Body Size and Tracheal Function in Insects

Arizona State University, Scottsdale AZ

Investigators

Abstract

Like all animals, insect cells must obtain oxygen from the atmosphere, and excrete the volatile waste product, carbon dioxide. Insects use a relatively unique type of respiratory system to engage in this process, the tracheal respiratory system. With the tracheal respiratory system, gases move between the atmosphere and the cells primarily via air-filled tubes called trachea. The goal of this study is to investigate the basic physiological mechanisms of function in the insect tracheal system, primarily using grasshoppers as model systems. Specifically, this project will assess the relationship between structure and function comparing insects of different sizes, and insect tissues of different metabolic rates. Tracheal structure will be measured using light and electron microscopy to quantify tracheal dimensions, while tracheal function will be assessed by monitoring gas exchange and ventilation volume in response to exposure to low or high oxygen levels. The relative importance of diffusion and convection in insect tracheal systems will be investigated by manipulating the diffusion rate of oxygen by changing the inert gas composition of the atmosphere. This research will be important for understanding the evolution of the insect tracheal system, and for developing a general understanding of the relationship between form and function in animal gas exchange systems. Because oxygen availability influences growth and development, this research will be relevant to the understanding of insect development, and the use of controlled atmospheres to reduce insect infestations. This research project will also contribute significantly to scientific training, as 2-3 Ph.D. students will be partially funded by this award.