Emerald Ash Borer beetle (Photos courtesy of the Maryland Department of Agriculture)

Reader Tim Feely e-mailed Living in LoCo over the weekend inquiring about the "mysterious looking purple boxes dangling from trees" around Loudoun. Tim noticed them when driving along Evergreen Mill Road in Leesburg and along parts of Loudoun County Parkway in Ashburn.

Tim, your assumption is correct. The purple boxes are for trapping insects, specifically the Emerald Ash Borer, an invasive green beetle from Asia that is rapidly destroying ash trees in a number of states from Michigan to Virginia. In 2007, an infestation was discovered in Herndon.

To find out if the infestation is spreading to surrounding areas of Northern Virginia, the Virginia Department of Agriculture has employees hanging these purple boxes near ash tree clusters in Loudoun and neighboring counties.

Seth Walton of Hillsboro said that in late April he started hanging about 150 of these sticky traps in parts of Loudoun, Clark and Fauquier counties. Starting next week, Walton will begin checking the traps for the noxious insect and will forward any suspicious specimens to the state's agricultural department for identification and further study. Debra Martin with the Virginia Department of Agriculture estimates that about 600 traps will be located throughout Loudoun. The traps will be taken down in August.

Damage caused by the Emerald ash borer beetle.

Debbie Dillion, LoCo's Urban Horticulturalist, said that Loudoun has not had a confirmed finding of the Emerald Ash Borer.

The insect is responsible for the death and decline of more than 30 million ash trees in Michigan since its arrival in the mid-1990s, according to this USDA study. Experts say that if the Emerald Ash beetle spreads to other parts of the United States, it most certainly will affect the country's timber industry. The eastern U.S. produces nearly 114 million board-feet of ash saw timber, says the USDA - a $25.1 billion industry. The wood is used for such items as tool handles, baseball bats, furniture and even paper.

The USDA also cites that a beetle infestation would add $7 billion in costs to state and local governments and landowners over the next 25 years to remove and replace infected and dead trees.

Last August - in an ongoing effort to fight the migration of the Emerald Ash Borer - Loudoun was placed under a quarantine to restrict the movement of ash lumber and firewood from Loudoun to non-quarantined sites.