Bronze Birch Borer

• Main Authors: S. A. Katovich, A. S. Munson, J. Ball, D. Mccullough
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Rarely attacked; British Columbia; Canada; Newfoundland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.175.8139; http://www.na.fs.fed.us/spfo/pubs/fidls/bbb/bbb.pdf

native to North America. Records from the late 1800’s and early 1900’s describe widespread damage to ornamental birches, especially in the Northeastern United States and Canada. In the 1920’s and 1930’s, the bronze birch borer was widely reported to be associated with dying birch trees in forests and woodlands. Today, this borer often contributes to mortality of woodland birch during severe drought or other stress. It is also an important pest of landscape birches (figure 2). The bronze birch borer occurs throughout the range of birches in Canada from Newfoundland to British Columbia but is most common in the southern portion of the provinces. In the United States, it is distributed from Maine, across the Great Lakes region to the Cascade Mountains of Oregon and Washington, and from Maryland to Kansas. Hosts Bronze birch borers are known to attack all native and introduced birch species, although birch susceptibility varies. Many varieties of birch species as well as numerous crosses between species are currently planted as ornamentals in North America. Although some varieties are more resistant tha n others, Figure 1. Bronze birch borer adult and two D-shaped exit holes. none are immune to birch borer attack. Generally, the white-barked birches are more susceptible than those without white bark such as river birch, sweet birch and yellow birch. Within the whitebarked birches-- paper birch and gray birch-- show more resistance than do many of the introduced species. 1