Effect of Temperature on the Equilibrium Body Water Mass in the Mite Dermatophagoides farinae

Net water gain and loss by partially dehydrated female house dust mites, Dermatophagoides farinae, were measured in several combinations of water vapor activity (av) and temperature. At some specific av's and temperatures experimental mites continued to dehydrate while at others mites rehydrated by extracting water from ambient water vapor. The lowest av at which a net gain of water occurred (critical equilibrium activity, CEA) was directly proportional to temperature; CEA's were 0.69 at 35 C, 0.63 at 30 C, 0.58 at 25 C, and 0.52 at 15 C.