Enlisting an underappreciated clientele: Public participation in distribution and evaluation of natural enemies in urban landscapes

Since the turn of the century, there has been a significant shift in the population of the United States from a rural to a predominately urban and suburban society. The process of urbanization created new landscapes to replace the natural areas or farms that previously occupied the land. To a great extent, these landscapes are artificial communities comprised of diverse assemblages of native and exotic species that may be comparable in diversity to tropical rain forests (Owen 1983). With respect to woody ornamental plants alone, Frankie and Ehler (1978) reported 322 species (132 species of trees, 147 species of shrubs, and 53 species of vines and ground covers) were planted in Austin, TX, and 123 species of trees were planted in Berkeley, CA. In total, 318 plant species, including 143 native and 175 non-native, exotic species, were planted in a single study garden in Leicester in the United Kingdom (Owen 1983). These urban landscapes, which include both annual and perennial species planted at densities or separations not normally found in natural habitats, also are characterized by high levels of patchiness and structural diversity (Owen 1983, Flanders 1986). In addition, the physical barriers associated with buildings, transportation corridors, parks, and industrial complexes add significant levels of artificial spatial complexity to the environment (Frankie and Ehler 1978).