Isidro Chacón

The Neotropical butterfly genus Colobura Billberg, 1820 (Nymphalidae) includes widespread, common and conspicuous species whose taxonomy one might expect to be well understood. Using integrative taxonomy—combining morphology (genitalia, larval traits, adult wing patterns, and UV reflectance), genome sequencing (mitochondrial barcodes, complete mitogenomes, and nuclear genomes), and life history data—we describe Colobura cryptica Sapkota, Orellana & Willmott sp. nov., a new species previously conflated with Colobura annulata. Key diagnostic morphological traits include: (1) a shorter third submarginal line on the ventral forewing that does not reach the pale cream transverse band, and (2) velvet-black larvae that lack yellow rings between segments or yellow spots at anterior edge of segments. Phylogenomic analyses resolved four distinct clades, with C. cryptica forming a genetically divergent lineage that is broadly sympatric with its sister species C. annulata. We further demonstrate a biogeographical split in C. dirce populations across the Andes and redefine the ranges of C. dirce wolcotti and C. dirce dirce. Genome sequencing showed that C. d. wolcotti, previously thought to be restricted to the Caribbean Islands, is also present in Central America and coastal Ecuador/northern Colombia west of the Andes, whereas C. d. dirce occurs only east of the Andes. This division corresponds with differences in ventral UV reflectance, which is strongly expressed in C. d. wolcotti but reduced in C. d. dirce. We conducted a preliminary investigation of UV-reflectance on the ventral wings and found evidence for differences across the four taxa, and we discuss the possibility of UV-mediated reproductive isolation that might have contributed to speciation in Colobura.

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.