Carbon dioxide release in Coptotermes formosanus Shiraki and Reticulitermes flavipes (Kollar): effects of caste, mass, and movement

Movement and carbon dioxide (CO2) release of individual Formosan, Coptotermes formosanus Shiraki and Eastern, Reticulitermes flavipes (Kollar) subterranean termites were recorded simultaneously in real time. Worker, soldier, and pre-alate (nymph) caste termites were recorded over 1-h periods at ambient temperature and normoxia in dry, CO2-free air. No evidence of discontinuous gas exchange cycles (DGCs) was observed in 344 recordings. Intensity of movement was constant in video tape recordings of termites under respirometry conditions. Duration of movement did not have a significant effect on residuals of V̇CO2 regressed on mass. Thus, movement did not effect V̇CO2 for these two species. Overall CO2 release values were calculated for all recordings resulting in mean V̇CO2 (ml CO2 g−1 h−1), and compared among caste, colony, and species with a nested ANOVA. There was significant interaction (P=0.0161) only for species. Mean CO2 release was significantly greater for R. flavipes (0.507 ml CO2 g−1 h−1) than C. formosanus (0.310 ml CO2 g−1 h−1). Mass scaling of termite V̇CO2 was investigated by regressing log10 V̇CO2 on log10 mass. The overall model combining species gave a mass scaling coefficient of 0.861(±0.0791), which approximates a previously published value for the arthropods as a whole (0.825).