Arthropods of the Washington, D.C., Area, Emphasizing Dyke Marsh Wildlife Preserve and Rock Creek Park Edward M. Barrows, Daniel S. Kjar, Christianne R. Bird, Bao Q. Chung, Toan Q. Chung, and Matthew R. Minor Laboratory of Entomology and Biodiversity Georgetown University Washington, D.C Figure 3. ADMWP. Figure 2. AWDCAD. The 11 National Capital Parks may have over 6,000 arthropod species, including centipedes, daddylonglegs, diplurans, insects, isopods, millipedes, mites, proturans, spiders, springtails, and ticks. Arthropoda is the most diverse animal phylum in the Washington, D.C., Area. Arthropods are key organisms that provide many ecosystem services. They include aerating soil, controlling population sizes of other organisms through parasitism and predation, pollinating, recycling nutrients, and serving as food for other organisms. Since 1975, the Laboratory of Entomology and Biodiversity (LEB) has been observing local arthropods in the Parks, concentrating on Dyke Marsh Wildlife Preserve (DMWP) and Rock Creek Park (ROCR). Materials and Methods Our lab collected information on DMWP arthropods by visual sampling from 1995 – 2003; Malaise trapping, 1998 – 1999; pitfall- trapping, 2000 – 2003; and soil-core sampling, 2002 – The lab collected information on ROCR arthropods from 1975 – 2003 by visual sampling. The lab performed an extensive literature search for arthropod species, present or expected in the Washington, D.C., Area. Results Our lab produced three searchable, on-line databases that regard National Capital Parks. The Biodiversity Database of the Washington, D.C., Area (BDWA) contains annotated images of 1,000s of local arthropods and other organisms (Figure 1). Arthropods of the Washington, D.C., Area: A Searchable Online Database (AWDCAD) contains over 12,000 records of arthropod species of Washington, D.C.; Delaware, Maryland, New Jersey, Pennsylvania, Virginia, and West Virginia (Figure 2). This database includes records from ROCR and DMWP. Arthropods of Dyke Marsh Wildlife Preserve, Virginia: A Searchable Online Database (ADMWPD) contains records of over 1000 arthropod species and morphospecies from DMWP (Figure 3). Discussion Our lab plans to continue adding data to the three databases in the forthcoming years. This information is useful for managing National Capital Parks in view of the many threats that these Park face. They include air, light, noise, soil, and water pollution; alien, invasive organisms; and possible pesticide use against mosquitoes that carry the West Nile Virus challenge the Parks. Acknowledgements We thank Friends of Dyke Marsh, Georgetown University, the National Park Service, and the Washington Biologists’ Field Club for supporting our research. Literature Cited Barrows, E. M. and D. S. Kjar Arthropods of Dyke Marsh Wildlife Preserve, Virginia: A Searchable Online Database (ADMWPD). Website. Barrows, E. M. and D. S. Kjar Biodiversity Database of the Washington, D.C., Area (BDWA). Website. Barrows, E. M., D. S. Kjar, C. R. Bird, B. Q. Chung, T. Q. Chung, and M. R. Minor Arthropods of the Washington, D.C., Area: A Searchable Online Database (AWDCAD). Website. Figure 1. BDWA.