An overview of the CO2 release patterns of lower termites (Isoptera : Termopsidae, Kalotermitidae, and rhinotermitidae)

This paper reviews recent studies of respiratory physiology in the lower te rmites (Kalotermitidae, Rhinotermitidae, and Termopsidae). Most information focuses on differences in CO2 release patterns among families, and between castes of Coptotermes formosanus Shiraki and Reticulitermes flavipes (Koll ar). Cyclic CO2 release (CCR), where CO2 is released at alternating high an d low rates, in the Isoptera is discussed, along with the lack of true disc ontinuous gas exchange cycling (DGC). Various hypotheses regarding the presence and absence of CCR in the Rhinote rmitidae are proposed. Discussions of the current evidence refuting the two hypotheses for the adaptive significance of DGC in arthropods are presente d. A new hypothesis for the adaptive significance of DGC (or CCR) is propos ed.