Mirmecofauna of the Floresta Nacional de Chapecó, Field I, was studied by weekly collections from December of 2003 to December of 2004. Malaise, pit-fall, sardine baits, glucose baits, sweeping net, entomological umbrella and Berlese funnel had been used. Three vegetal constitutions where showed, like pinus, eucalyptus Ombrófila Mista and Estacional Decidual native forests. 137.019 specimens of nine subfamilies, 18 tribes, 36 generas and 121 species were captured. The indices of diversity of Margalef were 9.9; 9.7 and 12.6; of Shannon and Wiener 3.0; 3.2 and 3.4 and of equitability of 0.69; 0.73 and 0.74, for the areas with pinus, eucalyptus and native forest, respectively. These results indicate a more uniform distribution in the community of the native forest, characterizing itself as an important reservoir species of ants in the West region of the Santa Catarina State, Brazil.
formicidae; biodiversity; samplings