Abstract
Hebert and colleagues (2004) used a short region of the mitochondrial Cytochrome oxidase subunit I gene as a delimiter for ten putative species from among 466 individuals of the skipper butterfly currently known as Astraptes fulgerator from Guanacaste, Costa Rica. Their data are reanalysed to assess cluster stability and clade support using Neighbor‐Joining bootstrap, population aggregation analysis and cladistic haplotype analysis. At least three, but not more than seven mtDNA clades that may correspond to cryptic species are supported by the evidence. Additional difficulties with Hebert et al.’s interpretation of the data are discussed.