Discovery and lectotype designation of Longitarsus californicus (Motschulsky) (Coleoptera, Chrysomelidae, Galerucinae, Alticini)

The lectotype of <i>Longitarsuscalifornicus</i> (Motschulsky, 1845) is designated, described, and illustrated. An illustrated key to eight light-colored <i>Longitarsus</i> species known to occur in the western United States is presented. A brief history of Russian entomological collecting in North America during the first half of 19^th century, with specimens preserved in Zoological Museum of Moscow University, Moscow and Zoological Institute, St. Petersburg, is provided.