Diversity and distribution pattern of butterflies at emerald forest reserve, Ikoyi, Osun state, NigeriaUN STATE, NIGERIA.

Butterflies are key pollinators and crucial indicators of ecosystem health. Studying these beneficial cluster organisms is important to develop conservation strategies at Emerald Forest Reserve. This study aimed to assess the species’ occurrence; the species’ richness and abundance; and the habitat preferences at site. Field sampling was conducted (October to December 2023) using transect walks and hand netting method across three sites: upper slope, lower slope, and valley bottom (each divided into three 200m transects and surveyed twice), ensuring data consistency. Data were analyzed using SPSS version 21. Species occurrence and abundance were represented in tables and percentages. One-way ANOVA was conducted to test for significant differences in species composition across the slopes. Data were evaluated using Shannon diversity index, Simpson’s diversity index, Pielou’s Evenness, and Margalef’s species richness index. A total of 406 butterflies belonging to 31 species, 23 genera, and 5 families were identified. Nymphalidae were highest in abundance and species richness (70.97%) of the total abundance representing 22 species, while the least family Lycaenidae was represented by one species (3.23%). There was no significant difference in species composition (P>0.05). The highest Shannon diversity index was at the Upper slope (H=2.55). The upper slope had the highest species richness index (R=3.50). Simpson’s diversity index indicated higher species diversity in the Upper slope and Valley bottom (D=0.91 each). In Upper slope, Hypolimnas anthedon, Leptosia alcesta, and Ypthima asterope were abundant. Hypolimnas anthedon, and Ypthima asterope, were species found at the Lower slope. At the Valley bottom, Euphaedra medon, Junonia sophia, and Euriphene amicia amicia were mostly in abundance. This study provided information on butterfly species occurrence, richness, and abundance across habitats while highlighting the ecological value of specific microhabitats. Integrated conservation strategies involving floral diversity protection, continuous monitoring of butterfly-plant association and reducing human pressure are indispensable.