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story from the magazine (June 2000)
Charting Asian Longhorned Beetles' Roaming
Habits By Erin
June 25, 2003
If the Asian longhorned beetle (ALB) continues its advance, this
invasive pest may potentially alter the makeup of North American hardwood
forests. Losses to lumber, maple syrup and tourism industries--dependent on
healthy hardwood trees--could reach $670 billion.
Now Michael T. Smith, an Agricultural Research Service entomologist
at the Beneficial Insects Introduction
Research Unit in Newark, Del., has generated new dispersal data that
predicts how far the beetle might spread once it begins to invade an area.
This formidable pest was first found in the United States in
1996, a stowaway amidst wooden crates from China. Since then, it's been
invading hardwood trees in the East, leaving an indelible mark on New York City
and Chicago parks. More than 7,500 trees have succumbed to the pest. Its
ravenous larvae feed inside trees, weakening them and disrupting vital nutrient
Determining ALB presence has depended solely upon visual
surveys. For this, crews climb host trees--like maple and elm--in search of
beetle activity. They scan for small markings where eggs are laid under the
bark and for dime-sized holes indicating an adult beetle has exited the tree.
Just as it sounds, locating these subtle signs of ALB infestation is
time-consuming and costly.
Beetle surveys and the methods used to establish quarantine
boundaries have been missing something. That important piece of the ALB puzzle
is an increased understanding of the beetle itself--more specifically, how it
moves in the environment.
Realizing this, Smith and colleagues conducted the first ALB
dispersal research in the beetle's home territory of Gansu Province, China.
They marked and released almost 40,000 beetles, collected from nature, and
tracked their movements. Their finding? The beetles fly much longer distances
than originally thought--even females carrying eggs.
This new dispersal data could be used to establish more reliable
survey and quarantine boundaries, increasing the chances of successful
ARS is the USDA's chief
scientific research agency.