Water vapor absorption in arthropods by accumulation of myoinositol and glucose

Hydrophilic soil arthropods have been thought to respond to soil desiccatio n exclusively by migrating to deeper soil Layers. Numerous studies have sho wn that their survival below 90 percent relative humidity dry weight, is Li mited to hours. However, Little attention has been paid to physiological ad aptations to more realistic desiccation regimes, such as at the permanent w ilting point of plants (98.9 percent relative humidity). A water vapor abso rption mechanism is described that allows a common soil collembolan, Folsom ia candida, to remain active down to below the permanent wilting point. A r eevaluation of the water physiology of this widespread and diverse animal g roup is required.