Comparative Desiccation Tolerance in Seven Species of Millipedes

Seven species of millipedes were subjected to desiccation and found to differ significantly in their tolerance to this stress, particu- larly at lower humidities. In general, larger species showed greater sur- vival but differences in cuticular permeability were also involved. Differ- ences in ability to retard water loss appeared to play no role in de- termining microhabitat preferences but correlated well with relative abundance of the millipedes. Tolerant species are more numerous be- cause of increased ability to disperse to new locations during unfavorable periods.