Ten species of Lachesilla, belonging in species group Forcepeta, are here described and illustrated; three of them occur exclusively in the United States, six are exclusive to México and one occurs mostly in Mexico, extending also to Guatemala. They differ among themselves, and are separated from other species in the group, mostly on genital characters. The location of the types is indicated in each description.
Keywords: lachesilla, forcepeta group, new species, U.S.A., Mexico