Species Composition of Diptera (Flies) in the Robalo River on Navarino Island, Chile

1. Species Composition of Diptera (Flies) in the Robalo River on Navarino Island, Chile Rebecca Wilson, Department of Biological Sciences, College of Arts and Sciences & Honors College James H. Kennedy Department of Biological Sciences, College of Arts and Sciences Abstract Introduction Methods Future Studies Adult Diptera will be sorted from Malaise trap collections and larvae from in-stream samples. The specimens will be identified to family, with the adults eventually identified to species. The project will begin with the specimens of the family Empididae (dance flies) (Figure 2). This family is composed of small, predaceous flies that are commonly referred to as “dance flies” due to their courtship displays. After the adult Empididae specimens have been identified, specimens from other families such as Tipulidae (crane flies) and Blephariceridae (net-winged midges) (Figure 3) may also be looked at. Identification of the specimens will begin with general guides to the genera. A primary resource will be The Manual of Central American Diptera Volumes 1 &2 (Brown et al 2008 and 2010). For the species level, Diptera of Patagonia and South Chile (J. E. Collin, 1933) will be used for a starting point. Further identification will rely on revisions and descriptions published in more recent literature. Assistance with this process will be asked for from recognized specialists, and all identifications will be verified by recognized experts. Representative specimens of all species identified will be deposited in UNT’s Elm Fork Natural Heritage Museum. Specimens will also be deposited in museums as appropriate. Select groups of Diptera, where DNA barcode standards has been established , will be barcoded. DNA barcoding is a technique that uses a short DNA sequence from a standardized and agreed-upon position in the genome as a molecular diagnostic for species-level identification. This has been done before with Empididae species (MacDonald, 1999) so with funding it would be possible to perform the same procedure with the Navarino Island samples. The Cape Horn Biosphere Reserve in Southern Chile is considered to be one of the last remaining wilderness areas in the world. While the vertebrates of the area have been described in detail, little is currently known about the invertebrates, in particular the aquatic insects, which live there. Much of the area is still in pristine condition, but is under threats from invasive species and tourism. As part of an ongoing project, specimens of the order Diptera (flies) will be selected from the three years worth of samples collected from the Robalo River on Navarino Island, Chile. These specimens will be identified to the species level and give future research in the area a base level of diversity to compare against. The Robalo watershed is located on Navarino Island, Chile, which is in the sub-Antarctic ecoregion. This watershed supplies the drinking water for the southernmost city in the world, Puerto Williams. It is part of the Cape Horn Biosphere Reserve and is one of the most pristine watersheds in the world (Anderson and Rosemond 2007). The region is experiencing increased human development that has the potential to impact the watersheds and its inhabitants. While the vertebrates of the region, both native and invasive, have been heavily researched, little is currently known about the freshwater invertebrates (Moorman, 2006). Insects were collected both in-stream and with Malaise traps, which collect flying insects, from 2007 -2010 at different points along the length of the Robalo River. From these samples, a large number of aquatic Diptera were found. Acknowledgments Tamara Contador, for providing the samples she worked so long to collect, and for the larvae photos. Bibliography Objective Anderson, C.B. and Amy D. Rosemond, 2007. Ecosystem Engineering by invasive exotic beavers reduves in-stream diversity and enhances ecosystem function in Cape Horn, Chile. Ecosystem Ecology, 154: 141-153. Brown, B.V., Borkent, A., Cumming, J.M., Wood, N.E., Woodley, and Zumbado, M.A. 2008 .  Manual of Central American Diptera: Volume 1. NRC Research Press, Ottawa, Ontario, Canada. Pp. Brown, B.V. Borkent, A., Cumming, J.M., Wood, N.E., Woodley, and Zumbado, M.A. 2010 .  Manual of Central American Diptera: Volume 2. NRC Research Press, Ottawa, Ontario, Canada. 728 pp. Collin, J. E., 1933. Diptera of Patagonia and South Chile, Based Mainly on Material in the   British Museum (Natural History); Part IV -- Empididae. MacDonald, John F., and James R. Harkrider, 1999. Differentiation of Larvae of MetachelaCoquillett and NeoplastaCoquillett (Diptera:Empididae:Hemerodromiinae) Based on Larval Rearing, External Morphology, and Ribosomal DNA Fragment Size. Journal of the North American Benthological Society 18: 414-419. Moorman, M.C., C.B. Anderson, A. Gutiérrez, R. Charlin, & R. Rozzi, 2006. Watershed conservation and aquatic benthic macroinvertebrate diversity in the Alberto D’Agostini National Park, Tierra del Fuego, Chile. The Anales 34: 41-58. Ricardo Rozzi, Juan J Armesto, Bernard Goffinet, William Buck, Francisca Massardo, John Silander, Mary TK Arroyo, Shaun Russell, Christopher B Anderson, Lohengrin A Cavieres, and J Baird Callicott. 2008. Changing lenses to assess biodiversity: patterns of species richness in sub-Antarctic plants and implications for global conservation. Frontiers in Ecology and the Environment6: 131–137. The goal of this research is to develop a comprehensive knowledge of the diversity and biological roles of the Diptera in this river. This documentation is needed before their populations and diversity is compromised by human activity. Figure 1. The sub-Antarctic ecoregion, showing the location of Navarino Island (Rozzi et al. 2008) Figure 2. An Empididae larva Figure 3. A Blephariceridae larva