scarabaeinae community structure was compared in two habitats with different degrees of conservation: a native forest at pampa del indio provincial park, and a forest fragment at los alisos cattle farm. pitfall traps baited with carrion and cattle dung were left open for 72-hour periods in october, november and december 2006. 769 adults belonging to six tribes, 11 genera and 26 species were captured in all. at los alisos, ontherus sulcatus fabricius and onthophagus hirculus mannerheim were the dominant species. trichillum sp., canthon podagricus harold, malagoniella sp., gromphas lacordairei brullé, and two dichotomius hope species were only found at los alisos, whereas canthon septemmaculatus latreille and coprophanaeus jasius olivier were exclusively collected in pampa del indio. number of individuals and diversity were significantly higher at pampa del indio. the same proportions of coprophagous and necrophagous species were captured at los alisos, with most having endocoprid and paracoprid habits. pampa del indio was characterized by the presence of rollers and necrophagous species. this research is the first study of forest scarabaeinae biodiversity in chaco province.