Diversity of moths and butterflies of the southwestern region of Costa Rica

Introduction: The Costa Rican southwestern region is considered one of the neotropical biodiversity hotspots. This geographically isolated forest embraces a rich diversity of moths and butterflies, which is still unknown for the most part. Objectives: (a) Describe and compare the diversity of moths and butterflies among different localities of the southwestern Costa Rican region, and (b) identify information gaps in this group of insects. Methods: Data for this study were collected in 12 different localities by parataxonomists and taxonomists for the national inventory of biodiversity led by INBio (National Biodiversity Institute) using different trap types, but relying mainly on light traps. We compared alpha and beta diversity of moths and butterflies among the six localities (Cortés, Piedras Blancas, Rancho Quemado, Agujas, Los Patos, Sirena) with more extensive sampling. Results: The dataset consisted of 78 747 specimens, of which 2 096 were identified only to the order level. The remaining 76 650 specimens were classified to the family level (n = 48 families), genus, species, or morphospecies. Species and morphospecies were distributed across 37 families. The alpha and beta diversity varied across localities for the 12 families of moths and butterflies that were present in the six localities selected. In general, Piedras Blancas, Rancho Quemado, and Sirena stand out as the most diverse localities. The richness of species varied among different families. For most families Agujas, Los Patos, and Sirena contained more species, but some other families showed a different pattern. Conclusion: Differences in the diversity of moths and butterflies over a northern-southern gradient likely correspond to species (individuals within species) adapted to different biotic (e.g., availability of host plants and food resources) and abiotic (e.g., microclimatic conditions associated to the complex topography of the region) conditions. Despite the large effort made by INBio in knowing and mapping the biodiversity of Costa Rica, and the economic and biological importance of the biodiversity, there are still a huge number of species to be known, named, and properly used.