Multipurpose Constructed Treatment Wetlands in the Arid Southwestern United States: Are the Benefits Worth the Risks?1

Multipurpose constructed treatment wetlands are being used increasingly in the southwestern U.S. to reclaim water, provide habitat for wetlands wildlife, educate the public on issues related to water and wildlife conservation, and fulfill other goals. Whereas, man-made wetlands have proven effective for water treatment, one serious drawback is the potential of some wetlands to produce large numbers of pathogen-transmitting and pestiferous mosquitoes. In regions of rapid human development, the juxtaposition of wetlands, which contain reservoirs and vectors of the causative agents of human disease, and human developments, which may contain avian reservoirs capable of rapid arbovirus amplification, are a concern to public health officials. Population trends of immature and adult mosquitoes differ markedly among wetlands receiving water that differs in quality and differing in coverage by vegetation. Four case studies are discussed in terms of mosquito production and