The USNM Geometridae Collection holds approximately 350,000 specimens,
3,303 of which are primary types.

The strength of the collection is definitively the New World, Nearctic and Neotropical, but the Old World is fairly well represented in number of species, especially from South East Asia, Europe and Africa.

Contributing collectors include, among others: Schaus (NW), Sullivan (NW), Barnes (USA), Blanchard (USA), Ferguson (USA), Kimball (USA), Glaser (USA), Sperry (USA), Davis (USA, Chile, Venezuela, Taiwan), Heppner (Venezuela, Peru), Dognin (NEO), Becker (NEO), Gentili (Patagonia), Peña (Chile), Hynd (England), Graham (China), Hevel & Steiner (Sri-Lanka), Pogue & Epstein (New Caledonia), Miller (Papua-New Guinea, Africa).

The collection is organized geographically by Region, then Systematically (Subfamily, Tribe) within each Region. The reasons for this organization are practical ones:

The expertise is predominantly by region. Our collection is not completely identified and we have to rely on outside help for identification of most of our backlog of unidentified material. Based on the requests received in past years and the way visitors work when identifying their specimens, having all the species for a particular region together, even if one taxon expands over more than one region, makes for easier access to the information.

There is no comprehensive, stable classification at the World level that can be followed. The only guide to all the names in Geometridae is the Catalogue of the Geometridae of the World (2001) by Scoble et al. which is alphabetical, and the family group names in Geometridae in Forum Herbulot which is systematic. The classification of the family is in flux, and only recently attempts to reconstruct the higher level classification on a world basis have begun.