Abstract
Changes in the composition of air among grain infested with the large strain of Calandra oryzae (L.) were investigated. The effects of these changes on adult and immature insects were determined. It r a s found that insects were killed by the depletion of oxygen and not by the build up of carbon dioxide. In general the large strain responded in the same way as the small strain, but some differences in the respiratory quotient of the two strains were noticed.