An exotic bark beetle that attacks elm trees, Scolytus schevyrewi, was discovered in the United States in April 2003. Since this time, S. schevyrewi, more commonly known as the banded elm bark beetle, has been found in 22 states. The new exotic bark beetle, S. schevyrewi, and an established exotic bark beetle, S. multistriatus, were studied to determine if competition exists and if one species is more successful with a limited resource. Beetle species were monitored for reproductive fitness using two host trees, American elm, Ulmus americana and Siberian elm, U. pumila. Both beetle species were reared in American and Siberian elm and placed in varying ratios in uninfested American and Siberian elm.