The water loss dynamics and humidity preference ofRhynehophorus cruentatus(F.) adults were investigated. Total body water averaged 47 ± 8% by mass, and cumulative loss increased with time at all humidities tested (0, 33, 63, and 100% RH) at 30°C. Death occurred more rapidly in low than in high humidities, at which time weevils had lost ≍50%of their total body water. Cuticular permeability of weevils calculated from exposure to 0% RH for 2 h was 39.5 ± 4.1 and 75.9 ± 8.1 μg cm−2h−1mmHg−1when surface areas were calculated using Meeh's formula and planimetry, respectively. When given a choice,R. cruentatusadults chose high over low relative humidity after exposure for 2 and 24 h.R. eruentatusadults are subject to desiccation under a drying environment and may use habitat location to conserve water.