North American Lepidoptera are divided among 62 taxonomic families according to Hodges Checklist of the Lepidoptera of America North of Mexico. Of these 62 families, the Geometridae, with over 1,400 species in the United States and Canada, represent the second largest family of Lepidoptera. The Geometridae are well known as "inchworm moths" for their distinctive larval form.

US and Canadian Geometridae are further divided among 6 sub-families, the Alsophilinae, Archiearinae, Oenochrominae, Ennominae, Geometrinae, Sterrhinae, and Larentiinae.

Friends' Central Summer Science Institute reports and images from recent collecting expeditions to New Mexico and Arizona.