Seasonal Changes in a Population of Desert Harvestmen, Trachyrhinus Marmoratus (Arachnida: Opiliones), From Western Texas

Other than a few of the common insects, we know little about arthropod populations in North American Deserts (Crawford, 1981). This seems to be especially true of arachnids. A few papers have appeared on desert spiders, solpugids (Muma, 1980a, 1980b and included references), desert scorpions (Polis, 1990) and harvestmen of southwestern New Mexico (Cokendolpher et al., 1993). Harvestmen, like other desert organisms, must synchronize their seasonal activity patterns with yearly changes in environmental conditions. In this paper, we provide information on the phenology of a population of the harvestman Trachyrhinus marmoratus, which is locally abundant on rocky slopes in the northern Chihuahuan Desert.