This long-term monitoring program is designed to characterize differences in the types of arthropod species (e.g., insects, arachnids) inhabiting different patches (e.g., desert remnants, agricultural fields, suburban yards, industrial properties) throughout the greater Phoenix metropolitan area. Understanding arthropod distributions and how they differ as functions of land use and land cover is important for several reasons. First, arthropods, with their diversity of life strategies, are good indicators of an array of features pertaining to habitat quality. Responses to changes in quality take place quickly due to the short life spans and the specialized requirements of many species. Second, arthropods provide a key link between plant and vertebrate communities so characterizing differences in arthropod assemblages as functions of land use and land cover is a key component of understanding the overall ecology of the urban environment.