Ambermarked birch leafminer (Profenusa thomsoni)(ABLM) is a significant pest of urban birch trees. Laval feeding causes a blotch mine on the upper leaf surface. Multiple larvae often feed inside one leaf, removing all the photosynthetic tissue. Severe infestations result in brown trees and early leaf fall. ABLM does not cause tree mortality, but repeated infestations can weaken birch trees, increasing susceptibility to fatal secondary pests and diseases. ABLM is native to Europe and was introduced to North America in the early 1900’s likely via nursery stock, and spread westward. In the late 1990’s ABLM was identified as the cause of significant defoliation of urban birch trees in Anchorage, Alaska and surrounding areas. ABLM can be controlled by the Ichneumonid parasitoid Lathrolestes luteolator. L. luteolator females lay a single egg inside developing ABLM, these eggs remain dormant until the larvae pupates, then hatch and develop, emerging the following summer as adult parasitoids. L. luteolator is native to North America but is not found in Alaska. A joint biological control project between the United States and Canadian Forest Services was initiated in 2003 to collect L. luteolator in Canada for introduction into Alaska. In 2003 the pre-release life history and distribution of leafminer in Anchorage was evaluated and collections made of L. luteolator parasitized ABLM larvae near Ft.Smith and Hay River, Northwest Territories, Canada. These larvae were allowed to pupate in tubs at CFS facilities in Edmonton, Alberta and overwintered, then shipped to Alaska in spring 2004 for final rearing in Anchorage.