Insects can tolerate a wide range of oxygen and carbon dioxide. Some insects can survive several days in the absence of oxygen by reducing their metabolic rates and utilizing the oxygen stored in their tissues. Other insects, when reared under low oxygen conditions, alter their tracheal system; growth of the trachea may vary inversely with the oxygen tension.
Excess carbon dioxide causes varied reactions in different insects. It is commonly used to anesthetize insects in the laboratory. Some insects can live in an atmosphere with high carbon dioxide for several days.
However, an excess of this gas in the atmosphere causes growth retardation in insects, such as silkworm and cockroaches. If the environment is high in carbon dioxide, the spiracles of insects tend to remain open, which may lead to excessive water loss.