Emerald ash borer and southern pine beetle

This guide covers two insects behind dying ash and pine: emerald ash borer and southern pine beetle. Both are covered by the Tennessee Division of Forestry's Protect TN Forests program.

Emerald ash borer

The beetle was first identified in Tennessee at a truck stop on I-40 in Knox County in July 2010, and 66 counties now have confirmed infestations. Putnam was among six counties added to the state's ash quarantine in June 2014, when WUOT reported ash made up about 3% of Tennessee's trees. The state and federal quarantines were lifted in 2021, but the Division of Forestry still asks people not to move firewood.

Signs

• Wilting leaves and dying branches that leave a sparse canopy.
• D-shaped exit holes in the bark, about 1/8 inch wide, visible year-round.
• More woodpecker damage on ash than usual.
• New shoots sprouting from the base or trunk (epicormic shoots).

Decline can take 1 to 3 years to show after infestation starts, with branches dying first and then the whole tree. Insecticides typically can't help a tree with more than 50% canopy thinning, and the Division of Forestry warns against cutting healthy, uninfested ash in a knee-jerk reaction. For advice on a specific tree, it suggests a county agent, a professional forester, or the Division at 615-837-5432.

Southern pine beetle

Loblolly, shortleaf, pitch, pond and Virginia pines are its favored hosts. Populations built to outbreak levels in 1998, and the outbreak that followed killed about 350,000 acres of pine in Tennessee, with losses of roughly $358 million.

Signs

• Pitch tubes, small blobs of resin, along the outside of the trunk.
• Crowns fading to red, or needles dropping.
• S-shaped galleries under peeled bark.

For an active spot, the Division lists cut and remove, cut and leave, cut and hand spray, pile and burn, or aerial pesticide applications. Timely thinning and harvests are its best prevention, and the Southern Pine Beetle Cost Share Program helps with that.

Report it

Protect TN Forests takes pest sightings through its Report A Pest form. If a dying ash or pine stands over a house, drive or line, have a contractor look at it sooner rather than later.