Abstract

Atmospheric methane is an important component in the process of global warming and ozone depletion. The biogenic sources are responsible for the majority of CH, fluxes (>70%). The contribution of each different source is still a question of debate. Insects like termites and cockroaches may contribute up to 20% of the total budget. Our trace gas detector (Fig. 1), consisting of a photo acoustic (PA) cell placed in the cavity of a CW liquid nitrogen cooled CO-laser, permits measuring methane (detection limit 1 ppb) and water vapour release together with CO₂ during the respiration of a single cockroach. This way the complex breathing pattern of this animal is observed, which demonstrates the sensitivity and speed of the detector (Figs. 2 and 3).

© 1994 IEEE