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

Abstract

Movement and carbon dioxide (CO 2) 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, CO 2-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 V ̇ CO 2 regressed on mass. Thus, movement did not effect V ̇ CO 2 for these two species. Overall CO 2 release values were calculated for all recordings resulting in mean V ̇ CO 2 (ml CO 2 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 CO 2 release was significantly greater for R. flavipes (0.507 ml CO 2 g −1 h −1) than C. formosanus (0.310 ml CO 2 g −1 h −1). Mass scaling of termite V ̇ CO 2 was investigated by regressing log 10 V ̇ CO 2 on log 10 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).