Respiratory gas exchanges of termites from the Sabah (Borneo) assemblage

Oxygen uptake and carbon dioxide release at 28 degrees C were determined in worker castes of twenty-six species of forest termites from the Danum Vall ey Conservation Area, south-east Sabah, by Warburg manometry. Metabolic rate varied inversely with body weight in a suite of soil-, wood/ soil- and wood-feeding species, giving a slope (in a log-log plot) of -0.63 . However, a number of large species, actively foraging forms such as Macro termes malaccensis, M. gilvus, Havilanditermes atripennis and Hospitaliterm es hospitalis, but also the wood-feeding Schedorhinotermes sarawakensis, sh owed an oxygen consumption greater than expected for their body weight. Rat es of methane emission were above 0.100 mu mol g(-1) h(-1) in seventeen spe cies, with very high fluxes in two wood/soil-feeders, Termes borneensis (0. 546 +/- 0.163 mu mol g(-1) h(-1)) and Prohamitermes mirabilis (0.303 +/- 0. 123 mu mol g(-1) h(-1)). Of the fifteen remaining species, seven were soil- feeders, five were wood-feeders, two were wood/litter-feeders and a single species fed on lichen and moss. Low or negligible CH4 emissions (< 0.100 mu mol g(-1) h(-1)) were observed in three other species, all wood-feeders. An apparent respiratory quotient (ROapp) was calculated using xCO(2) and XO 2 (corrected for methane emission, but not hydrogen). Mean RQ(app) was at o r above 1.00 in eleven species and between 0.95 and 1.00 in a further six s pecies, the two sets of species together representing all trophic groups, i ncluding lichen-feeders. This is argued to be consistent with carbohydrate being the principal substrate supporting respiration.