Generally, wood-lice are confined to habitats where the saturation deficit is low and damp surfaces are available. Cylisticus convexus (De Geer) is one of many species that are found in a relatively wet habitat (Edney, 1954). Allee (1926) was the first to report on some moisture reactions of C. convexus. When he supplied them with dry filter paper, they aggregated strongly to reduce water loss. When he supplied them with very dry paper in a dry atmosphere, the isopods all moved about frantically until they died. Those placed on moist filter paper, however, moved about slowly and remained apart--reacting very much as if they were in their normal habitat. Since a colony of C. convexus was available to me, I proceeded to investigate further the moisture reactions of this isopod. Several experiments were undertaken to examine their behavior under different humidity conditions, and to determine their preferred range of humidity. All tests were made in an olfactometer.
Wilson, Louis F.
"Some Relative Humidity Reactions of the Wood-Louse, Cylisticus Convexus (Isopoda: Porcellionidae) in an Olfactometer,"
The Great Lakes Entomologist, vol 1
Available at: https://scholar.valpo.edu/tgle/vol1/iss7/5