All the described butterfly and moth (Lepidoptera) species that are known to occur in Canada, Greenland, and the continental United States of America are listed. The editors have endeavoured to include information from all publications up to the end of December 2022, as well as from a few publications that were in press at that time. All valid scientific names, from order to subspecies, are presented following the most recent available classification. For all species-level names, the current genus, species name, author, date, and original genus are listed. All available (and many unavailable) synonyms are listed, as well as hundreds of misspellings, emendations, misidentifications, and misapplied names published in the past century. In total, over 36,700 taxon names are included in the list. A total of 13,084 species are reported, including one extinct species, one probably extinct species, twelve extirpated species, 151 strays, and 30 unverified records.
An additional 192 excluded species that have been reported in error from North America are noted, as well as 26 nomina dubia. A phylogenetic numbering system is employed for all valid species, and “MONA” Numbers from the previous checklist are also included. A total of 295 species are reported as introduced and twelve more are possibly introduced; 310 species are Holarctic, nine more are possibly Holarctic, and another 55 species are either Holarctic or introduced. Brief synopses of the 93 families reported from North America are given, and over 1,600 references are cited, covering the vast majority of relevant taxonomic revisions pertaining to the North American Lepidoptera fauna. More than 2,000 taxon notes provide information on introduced species, misidentifications, erroneous records, details of recent additions, and details of recent taxonomic changes and differing interpretations. The index lists all scientific names of Lepidoptera mentioned in the list.
A total of 81 new combinations, three new statuses, nine revived combinations, 22 revived statuses, 61 new synonymies, and seven revised synonymies are designated.