The 37-year ongoing inventory of the estimated 15 000 species of Lepidoptera living in the 125 000 terrestrial hectares of Area de Conservacion Guanacaste, northwestern Costa Rica, has DNA barcode documented 11 000+ species, and the simultaneous inventory of at least 6000+ species of wild-caught caterpillars, plus 2700+ species of parasitoids. The inventory began with Victorian methodologies and species-level perceptions, but it was transformed in 2004 by the full application of DNA barcoding for specimen identification and species discovery. This tropical inventory of an extraordinarily species-rich and complex multidimensional trophic web has relied upon the sequencing services provided by the Canadian Centre for DNA Barcoding, and the informatics support from BOLD, the Barcode of Life Data Systems, major tools developed by the Centre for Biodiversity Genomics at the Biodiversity Institute of Ontario, and available to all through couriers and the internet. As biodiversity information flows from these many thousands of undescribed and often look-alike species through their transformations to usable product, we see that DNA barcoding, firmly married to our centuries-old morphology-, ecology-, microgeography-, and behavior-based ways of taxonomizing the wild world, has made possible what was impossible before 2004. We can now work with all the species that we find, as recognizable species-level units of biology. In this essay, we touch on some of the details of the mechanics of actually using DNA barcoding in an inventory.