Species composition and diel variation of a butterfly taxocene (Lepidoptera, Papilionoidea and Hersperioidea) in a restinga forest at Itapuã State Park, Rio Grande do Sul, Brazil

Abstract

The composition and the hourly variation of butterfly species (Lepidoptera: Papilionoidea and Hesperioidea) throughout the day and the seasons was evaluated in a 1,000 m2 patch of sandy forest (Restinga forest) on a coastal plain at Itapuã State Park (30°22'S, 51°02'W), Viamão, Rio Grande do Sul, from July 2001 to June 2002. Butterflies were sampled by scanning and focal observations (adapted from ALTMANN 1974) carried out at successive 45 minutes intervals. This methodology proved to be effective in recording the presence and activity of butterflies on a small area. A total of 108 observation hours yielded 326 butterflies from 41 species, 33 genera and five families. Nymphalidae was the most abundant family contributing with 74% of the total individuals. The most abundant species was Eunica eburnea Fruhstorfer, 1907 (Nymphalidae) with 45 individuals registered along the year. General diversity estimates were Dmg = 6.912, H′ = 3.012 and d = 0.138. Although there were variations in the daily times of butterfly activity throughout the seasons, there was a general trend for higher activity during the morning period, between 9:00 and 11:45 h.