Odonata from the Lower Delta of the Paraná River, Argentina

Abstract

The first Argentine area surveyed from an odonatological point was Delta del Paraná (DP), a large wetland area of 14,000 km2 between Buenos Aires and Entre Ríos provinces, close to Buenos Aires city. This area has a typical delta landscape plenty of riverine and pond habitats and it is encompassed by two main rivers (Paraná de las Palmas and Paraná Guazú). It belongs to Delta and Parana Islands eco-region, which is represented by a narrow corridor of riparian forests following the Parana river from the northern limit of Corrientes province to DP. At the end of the 19th century and the first half of the 20th, human population increased in DP occupying large areas dedicated mainly to timber production and tourism. From the second half of the 20th century to now, land use change to low intensity tourism leaving large areas unexploited.During the past 20 years several field trips to DP increased the species inventory for this area to 43, being Libellulidae the family with more new records. The biogeographical relationship of DP with Humid Chaco and Paranaense Forest is still validated with these additions. In fact, except for six species, i.e., Andinagrion saliceti, Cyanallagma bonariense, Staurophlebia bosqui, Phyllocycla vesta, Erythrodiplax corallina, and Erythrodiplax nr. pallida, the remaining 37 (90%) species are also recorded in the Paranense Forest; but, from 25 genera recorded in DP, 36%, i.e., Telebasis, Peristicta, Staurophlebia, Triacanthagyna, Aphylla, Progomphus, Diastatops, Nephepeltia, and Oligoclada, are not recorded in the Pampas.