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The degree to which Northern Hemisphere paleoclimate drivers influenced its southern counterpart during the most recent deglaciation (2010 ka BP) is a hotly debated issue .In southern South America, the debate is primarily focused on the existence of an ACR-like, a YD-like, or a mixture of the two, cooling event at the end of the LGM. The only way to test rigorously the hypothesis of synchroneity (or otherwise), is to generate detailed quantitative palaeoclimatic records from under-represented areas in the Southern Hemisphere to clarify the climatic relationships between the Northern and Southern Hemisphere, and thus identify possible coupling mechanisms. Chironomids (insects) are particularly useful paleoenvironmental indicators, especially for reconstructing changes in temperature. Here I present the results of the first chironomid-based summer temperature reconstructions from southern South America. A training set of 60 taxa from 102 lakes in Patagonia (Argentina and Chile) located along a transect between 40 and 54°S were analysed and summer air temperature was identified as the main driver of chironomid distribution. This model will allow direct comparisons with emerging chironomid-based temperature reconstructions from New Zealand, Greenland and Antarctica ice core records. This study highlights the potential of chironomid-based reconstructions to extend and quantify the late Quaternary paleoclimate history in middle latitudes of South America References Alloway BV, Lowe DJ, Barrell DJA, Newnham RM, Almond PC, Augustinus PC, Bertler N, Carter L, Litchfield NJ, McGlone MS, Shulmeister J, Vandergoes MJ, Williams PW, NZ-INTIMATE Members (2007) Towards a climate event stratigraphy for New Zealand over the past 30 000 years (NZ-INTIMATE project). J Quat Sci 22:9 35. Bennett KD, Haberle SG, Lumley SH. 2000. The Last Glacial - Holocene transition in southern Chile. Science 290: 325-328. Brooks SJ. 2003. Chironomid Analysis to Interpret and Quantify Holocene Climate Change. In Mackay, A., Battarbee, R., Birks, J., Oldfield, F. Editors. Global Climate Change in the Holocene. Chapter 22, 328-342, Arnold Publishing, London. Dieffenbacher-Krall AC, Vandergoes MJ, DentonGH. 2007 An inference model for mean summer air temperatures in the Southern Alps, New Zealand, using subfossil chironomids. Quat Sci Rev 26:24872504. Hajdas, I, Bonani, G, Moreno, P and Ariztegui, D. 2003. Precise radiocarbon dating of Late-Glacial cooling in mid-latitude South America. Quat. Res. 59: 70-78. Heusser CJ. 1993. Late-glacial of southern South America. Quat. Sci. Rev. 12: 345-350. Heusser CJ, Rabassa J. 1987. Cold climate episode of Younger Dryas age in Tierra del Fuego. Nature 328: 609-611. Hoganson JW, Ashworth AC. 1992. Fossil beetle evidence for climatic change 18,000 - 10,000 years BP in south-central Chile. Quat Res 37: 101-116. Mancini, V. 2002.Vegetation and climate during the Holocene in Southwest Patagonia, Argentina Rev. of Palaeobotany and Palynology 122 ( 3-4) :101-115 Markgraf V. 1991. Younger Dryas in South America? Boreas 20: 63-69. Massaferro, J & M. Vandergoes. 2007. Postglacial Chironomid records from Australia, New Zealand and South America . Encyclopedia of Quaternary Sciences. MS 287: 398-409 p. Elias, S (Ed) Elsevier. Massaferro, J, Moreno, P.I, Denton, G.H, Vandergoes, M. and Dieffenbacher-Krall, A. 2009. Chironomid and pollen evidence for climate fluctuations during the Last Glacial Termination in NW Patagonia . Quat. Sci. Rev. 28: 517-525 Mourguiart, P., T. Correge, D. Wirrmann J. Argollo M.E. Montenegro M. Pourchet & P. Carbone, 1998 Holocene palaeohydrology of Lake Titicaca estimated from an ostracod-based transfer function . Palaeogeogr. Palaeoclimatol. Palaeoecol. 143 :5172 Sylvestre F. , 2002. A high resolution diatom-reconstruction between 21 and 17 kyr B.P. from the southern Bolivian Altiplano. J. of Paleolimnology, 27, 45-57 Walker, 1. R., J. P. Smol, D. R. Engstrom, and H. J. B. Birks. 1991. An assessment of Chironomidae as quantitative indicators of past climatic change. Can. J. Fish. Aquat. Sci. 48: 975-987.

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