The morphology and natural history of a common and widely distributed butterfly was observed over 25 years in Costa Rica. Recent DNA barcoding (DNA sequence analysis) showed that what was once thought to be a single species is actually a group of ten or more species that each constitute a clade. Though caterpillars of these species eat different food plants and have somewhat different habitat preferences than their adult forms, their morphological differences are subtle. This group of species would likely never have been identified as multiple species had it not been for considering which type of species concept