Cyclic CO(2) release in Cryptotermes cavifrons Banks, Incisitermes tabogae (Snyder) and I. minor (Hagen) (Isoptera: Kalotermitidae).

CO(2) release patterns of three drywood termite species were investigated using flow-through respirometry techniques. Eight hours of real-time CO(2) release data were recorded for pseudergates of Cryptotermes cavifrons Banks, Incisitermes minor (Hagen), and I. tabogae (Snyder) at 20-40 degrees C. Cyclic release of CO(2) was observed in 20-90% of C. cavifrons, 70-100% of I. tabogae, and 87-100% of I. minor pseudergates. Variability of the recordings (calculated as the coefficient of variability or CV) was used to estimate the level of cycling in each recording. CV ranged from 14.53+/-2.57 (40 degrees C) to 32.33+/-1.12% (30 degrees C) in C. cavifrons, 20.24+/-2.44 (35 degrees C) to 67.3+/-10.3% (20 degrees C) in I. minor, and 15.9+/-1.46 (35 degrees C) to 34.15+/-6.18% (20 degrees C) in I. tabogae. The relationship between temperature and CV for each species was modeled using non-linear regression. CV of both Incisitermes spp. decreased exponentially with temperature, while C. cavifrons CV followed a Gaussian model, indicating an optimal cycling temperature of approximately 30 degrees C. Mean V.CO(2) values were determined for each species as a function of temperature, and ranged from 0.1 ml CO(2) g(-1) h(-1) (I. minor at 20 degrees C) to 0.8 ml CO(2) g(-1) h(-1) (C. cavifrons at 40 degrees C). For all three species, V.CO(2) significantly increased linearly with temperature. Colinearity tests indicated that different models described the V.CO(2) relationship with temperature for both genera. Q(10) values for V.CO(2) over the range of 20-40 degrees C were 1.92 for I. minor, 1.66 for I. tabogae, and 1.62 for C. cavifrons pseudergates.