Respiration in insects is characterized by prolonged periods (in some cases up to several hours) in which no exchange of gases occurs and this pattern differs strongly from respiratory patterns in most mammals in which breath-holding is restricted to seconds or, at most, a few minutes. This research project will examine the relationship between metabolic rate and respiratory pattern in three representative insect species. Temperature, feeding, and atmospheric oxygen will be systematically varied as a means of producing varying ratios of metabolic output to oxygen availability. Under these controlled conditions, the pattern of respiration will be examined using flow-through respirometry. Release of carbon dioxide and water will be measured on a second-to-second basis. Specifically, this research will test the hypothesis that the critical factor in insect respiratory control is the regulation of internal oxygen levels as opposed to the reduction of water loss. The research will be conducted in conjunction with a graduate student engaged in her doctoral research, and with undergraduate students participating in the University of California, Irvine Excellence in Research program. Insects have major negative impacts on human society as vectors of disease and as destroyers of our food crops. The respiratory system of insects is both anatomically and physiologically distinct from that of mammals. As such, it is an excellent target for improved and safer insect control mechanisms. The proposed research will investigate how environmental factors impact the regulation and control of breathing in insects. The results should be of use in our ongoing attempts to disrupt insect breathing and metabolism as a means of controlling insect pests.
