Vol. 114. No. 4. September & October 2003 205 ADULT CHLOROPIDAE (DIPTERA) ASSOCIATED WITH CONSTRUCTED TREATMENT WETLANDS MODIFIED BY THREE VEGETATION MANAGEMENT TECHNIQUES' J. B. Keiper, M. Stanczak ; , and W. E. Walton' ABSTRACT: Eight genera of Chloropidae were collected from experimental wetland research cells manipulated by different vegetation control strategies in southern California, U.S.A. After flooding, chloropids were collected with detergent pan traps for 14 months. Eribolus californicus. a secondary invader of emergent wetland plants, was the only abundant species. Results indicate that density of adult Chloropidae was not affected differently by the wetland plant management techniques used. However, the techniques slowed the growth of emergent macrophytes (particularly bulrush, Schoenoplectus spp.) that are the sites of larval development. Therefore, first year data show low numbers of chloropids, with a two-to three-fold increase by year two. KEY WORDS: Chloropidae, Diptera, adults, wetlands, vegetation management techniques. Chloropid flies (Diptera: Chloropidae) represent a large family with about 1300 species worldwide (Rogers et al. 1991). Many species of chloropids are considered to be either primary or secondary invaders of plants, especially grass-es, sedges, and rushes (Valley et al. 1969, Todd and Foote 1987, Keiper et al. 2002, Beaulieu and Wheeler 2002). Other species appear to exhibit more scav-enging habits (Ferrar 1987, Keiper et al. 2002), and yet others are pest species that may be vectors of ocular diseases (Liohippelates, Siphunculina spp.) or cause damage to crops (Ferrar 1987). Most species are not anthropophilic. Wetland environments provide habitat and food for many chloropid species, and their abundance appears to be tied directly to the wetland plant diversity (Valley and Foote 1997). Large numbers of chloropid individuals and numerous species are frequently found in marsh areas (Todd and Foote 1987). However, due to damage caused by human activities, many wetland habitats are threatened, and the restoration or replacement of wetland areas is common practice today (Hammer 1997). Both comparatively old and newly constructed wetland areas are frequently subjected to vegetation management to prevent aquatic plants from eliminating open water areas. Excessive growth of vegetation in construct-ed wetlands can lead to decreased efficiency in treating wastewater (Marble 1992, Thullen et al. 2002), and provide less suitable habitat for waterfowl and other wildlife than a hemi-marsh (i.e. a marsh with approximately 50 percent vegetation cover and 50 percent open water) (Batzer et al. 1999). A recent paper showed that vegetation management reduced adult shore fly (Diptera: Ephydridae) densities, but populations required less than one year to produce 1 Received on August 2, 2002. Accepted on March 1 3, 2004. 'Department of Invertebrate Zoology, Cleveland Museum of Natural History, 1 Wade Oval Drue. Cleveland, Ohio 44106 U.S.A. E-mail: jkeiperdf cinnh.org. ' Department of Entomology, University of California. Riverside, California 92521 U.S.A. Mailed on August 25. 2004
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