A beetle that feeds on ash trees may be the greatest threat to become a major pest, according to the Agricultural Research Service's Systematic Entomology Laboratory.
Since its detection near Detroit in May 2002, the emerald ash borer, Agrilus planipennis, has devastated the ash tree population in areas of Michigan and forced quarantines there and in parts of Ohio and Ontario.
The metallic-green beetle, which feeds beneath the bark of green (Fraxinus pennsylvanica), white (F. americana) and black (F. nigra) ash trees, is indigenous to Asia. The borer, which probably entered the United States about five years ago in wooden packing material, could cause damage similar to that caused by the Asian longhorned beetle (Anoplophora glabripennis) and Dutch elm disease.
When first discovered, the bug stumped authorities trying to identify it. They sought help from the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS), which, in turn, sent specimens to SEL's Communications and Taxonomic Services Unit in Beltsville, Md.
The unit, led by entomologist Robert Carlson, helps solve taxonomic problems and provides identifications needed for carrying out APHIS' Plant Protection and Quarantine program. It also assists individuals and other agencies.
Carlson sent a sample borer to Richard Westcott, a cooperating entomologist with Oregon's Department of Agriculture, who confirmed its suspected immigrant status. Eduard Jendek, an entomologist with the Academy of Sciences' Institute of Zoology in Bratislava, Slovakia, made the final identification.
The emerald ash borer is one of more than 50 species of insects and mites newly identified in the United States by SEL since 1999.