Activities of Certain Species of Eleodes in Relation to Season, Temperature, and Time of Day at Joshua Tree National Monument (Coleoptera: Tenebrionidae)

Members of the genus Eleodes at Joshua Tree National Monument live under daily and seasonal environmental extremes. Overt activity is consonant with these conditions. The data from five different laboratory and fiield procedures indicate that surface activities generally occur when the ambient temperatures are between 12-28°C. As ambient temperature increases, Eleodes spp. select relatively cooler microhabitats; as ambient temperature decreases, Eleodes spp. select relatively warmer microhabitats. In the spring the insects are mostly diurnal; in the summer they are usually crepuscular or nocturnal; most beetles hibernate during the winter. Much of the activity period is spent foraging on small green herbs; however, individuals will eat almost any plant and sometimes animal material that they encounter. Inactive periods are spent in sheltered microhabitats such as rodent holes and crevices between rocks.