Comparative respiration and methane production rates in Nearctic termites

Abstract

Rates of oxygen consumption and the production of carbon dioxide and methane were measured in thirteen Nearctic termite species periodically, for 48h, at 25 °C. Decreased respiration rates were observed in several species with decreasing oxygen and increasing carbon dioxide levels. Those species with apparently higher moisture requirements (i.e. subterranean termites) generally had lower respiration rates compared with the dampwood (highest rates) and dry wood (intermediate rates) termites. Termite biomass significantly influenced respiration rates, with the largest species having the highest rates. Methane production occurred in seven of the thirteen species assayed. Of these apparently methanogenic species, only one of the eleven colonies of Incisitermes minor and one of the two colonies of Prorhinotermes simplex produced methane. The generally reduced respiration rates found at lower oxygen and higher carbon dioxide levels are considered more representative of the conditions encountered in termite galleries. Bioassays conducted under more natural atmospheric conditions may be more representative of termite responses in the field.