A review of the entomological literature revealed relatively few general studies on arthropods in urban environments, excluding those in the context of pest control or epidemiology, and all were limited in scope and duration. Most studies documented the presence and abundance of species in a variety of poorly quantified urban categories. There also were a number of studies on the effects of urban pollution and changes in arthropod community composition over time (particularly in urban green areas). From these studies, three groups of arthropods could be identified: (1) âruralâ taxa not present (or at lower abundance) in urban settings, (2) âurbanâ taxa present only (or at higher abundance) in urban settings, and (3) taxa present in both rural and urban settings with no particular affinity for either. The lack of a basic understanding of the mechanisms accounting for distributional and abundance patterns of urban arthropods illustrates the many opportunities for entomological research that exist in urban settings. Some of these opportunities are outlined to encourage further work on the ecology of urban arthropods.