D3421: Methodology for characterizing respiration in the common flesh fly, Sarcophaga bullata, during flight

In this research, we describe a method for recording respiratory responses in insects during low-energy and high-energy activities, such as resting or walking versus flight. Using Sarcophaga bullata, we investigated respiration by simultaneously monitoring oxygen (O₂) consumption and carbon dioxide (CO₂) production. Measurements of relative O₂ consumption and CO₂ production by individual flies were carried out after gluing a piece of stainless-steel foil to the scutum. Resting or walking flies were placed directly in a respiration chamber where the exchange of gases was recorded. For higher energy measurement, flies were tethered to a stainless-steel wire fitted with a neodymium magnet and suspended above the base of the chamber to stimulate flight. During the low-energy activity, we observed a predictable stoichiometric balance between the amount of O₂ consumption and CO₂ production. However, a significant increase in CO₂ production relative to O₂ consumption during high-energy activity indicates a shift from aerobic respiration to anaerobic respiration. The methods developed over the course of this research, and initial findings open new avenues to explore respiratory and metabolic responses of insects to a range of environmental factors, including exposure to sublethal levels of pesticides and pollutants, temperature fluctuations, disease, and dietary quality.