This data package contains counts and taxonomic identification of arthropods sampled by pitfall traps at the Jornada Basin LTER site from 1996-2001. The objective of this study is to observe how shifts in vegetation resulting from desertification processes in the Chihuahaun desert have changed the spatial and temporal availability of resources for consumers. Desertification changes in the Jornada Basin include changes from grass to shrub dominated communities and major soil changes. If grassland systems respond to rainfall without significant lags, but shrub systems do not, then consumer species should reflect these differences. In addition, shifts from grassland to shrubland results in greater structural heterogeneity of the habitats. We hypothesized that consumer populations, diversity, and densities of some consumers will be higher in grasslands than in shrublands and will be related to the NPP of the sites. Data on arthropods captured in pitfall traps at LTER III consumer plots (a subset of NPP plots) were collected at 2 month intervals. Data includes number of individuals, order, family, genus, and species. This data collection has been completed.