The Effects of Meal Quality on the Specific Dynamic Action and Respiratory Pattern of Insects

An organism’s specific dynamic action (SDA), or the increase in metabolic rate of an animal associated with processing a meal, is affected by a variety of metabolic factors including meal quality and exercise. Studies have shown that an increase in metabolic rate (SDA) has a direct impact on insect respiration patterns, but these studies have not examined the effect of meal content. It is well established that increasing meal energy content affects the SDA of vertebrates, however we are not sure what will occur in insect SDA or what will occur to the respiratory pattern of the insect if meal energy content is increased. The goal of our study was to investigate the effect of a protein caloric restricted diet and its effect on an insect’s respiratory pattern. Therefore, we examined the effect of increasing protein concentration in food (14%-24% egg albumen diluted within agar gel) on the respiratory rate and respiratory pattern of Gromphadorhina portentosa, using flow-through respirometry techniques. Because studies have shown that activity independently affects SDA, G. portentosa is an ideal organism because it has a sedentary lifestyle. Our results on insect SDA and its affects on respiratory pattern will provide researchers with perhaps another model system in which to study this physiological response.