Coleopterous egg deposition on alder leaves from the Klondike Mountain Formation (Middle Eocene), northeastern Washington

Flea beetle (Chrysomelidae) egg deposition has been found on three impressions of alder (Alnus parvifolia) leaves collected at a roadcut in Republic, Washington. These fossils were discovered by Wes Wehr (University of Washington, Burke Museum) during investigations of fossil plants from the Republic, Washington, area. These impressions represent a yet to be determined species, belonging to the genus Altica GeofFroy (1762). They represent the first member of this genus to be described from the Eocene of North America. The fossils were found in lacustrine rocks from the lower part of the Klondike Mountain Formation. Figure 1 represents the Republic fossil locality and the distribution of this Formation. A brief description of the geologic history of this region can be found in Wolfe and Wehr (1987). The Klondike Mountain Formation has a radiometric age that ranges from 42.3 ± 2.0 to 50.3 ± 1.7 m.y. (Pearson and Obradovich, 1977).