Six field trips were carried bimonthly, between July 2004 and July 2005, in three fragments of Decidual Seasonal Forest of Santa Maria, Rio Grande do Sul State: Morro do Elefante (E), Morro do Lar Metodista (M) and Morro Cerrito (C). After 135 sampling hours, 1594 butterflies of 145 species were registered. Among these, 59% are Nymphalidae, 19% Hesperiidae, 10% Papilionidae, 7% Pieridae and 5% Lycaenidae. Nine species were new registers for Rio Grande do Sul State. M had the highest richness and abundance of species. The lowest richness was observed in E and the lowest abundance in C. Shannon-Wiener and Margalef diversity indexes had the same ordination among localities, being higher in M, more heterogeneous and disturbed, and lower in E. Simpson and Berger-Parker dominance indexes were higher in E, with more abundant species, and lower in C. Only 30% of the species were common to the three localities. About half of the total registered species were exclusive from one of the three localities. The highest similarity indexes (Morisita and Jaccard) were obtained between M and E, and the lowest between E and C.
Butterfly; conservation; inventory; South Brazil; species richness
