WATER RELATIONS AND THERMAL SENSITIVITY OF SEVERAL COCKROACH SPECIES (DICTYOPTERA, BLATTIDAE AND BLABERIDAE)

1. Per cent total body water content (%TBW), cuticular permeability (CP), rate of water loss, critical thermal maxima (CTMax), and upper lethal limits (ULL) were determined for Pacific beetle, Diploptera punctata (Eschscholtz), Surinam, Pycnoscelus surinamensis (L.), and Turkestan, Blatta lateralis (Walker), cockroaches. 2. Initial body mass ranged from 153.16 to 464.96 mg, for D. punctata and P. surinamensis cockroaches, respectively. Mean % TBW was 57.8 for P. surinamensis and 67.7 for B. lateralis. 3. Mean cuticular permeability was not related to initial mass and ranged from 20.9 to 38.7-mu-g/cm2/hr/mmHg for D. punctata and P. surinamensis, respectively. 4. Cumulative mass loss and % TBW lost increased linearly with desiccation time. 5. CTMax ranged from 43.2-degrees-C for D. punctata to 44.3-degrees-C for P. surinamensis. There were significant, but small differences in CTMax among the three species. 6. ULL were 2.2 to approximately 4-degrees-C greater than CTMax. The greatest ULL was 48.1-degrees-C for B. lateralis and the lowest ULL was 45.0-degrees-C for D. punctata.