Adult Emerald Ash Borer

The emerald ash borer is a native of Asia and was introduced to America through infested shipping crates. This metallic green boring insect attacks and kills all species of ash trees, including white, green, blue and black.  Ash trees infested by this insect may exhibit a D-shaped hole on the trunk, where the mature boring beetle exits the tree. The borer can attack stressed, as well as healthy trees and can kill the tree usually within two to four years, depending on tree diameter and vigor.  The borer is currently found in Michigan, Ohio, Wisconsin, Maryland and Virginia.  If your ash trees are displaying suspicious symptoms, please contact the division.  For more detailed information about the emerald ash borer, please visit the U.S. Forest Service publication link at http://na.fs.fed.us/fhp/eab/.


Forest Tent Caterpillar (Malacosoma disstria Hübner):

Forest Tent Caterpillar Larvae	Silky Masses on Tips of Branches

The forest tent caterpillar is a native insect found throughout the range of hardwood forests in North America. It is more abundantly distributed in eastern North America, but is also common in western areas that have large stands of aspen. At times, this insect can be a damaging defoliator of trees. Trees that are defoliated often flush a new, smaller set of leaves in July. While forest tent caterpillar does not typically cause mortality to host trees, mortality can occur when populations interact with other disturbances, such as drought or insect outbreaks.

Forest tent caterpillar larvae use silk to form trails and to create pads on host trees where they congregate and rest. However, they do not construct and reside within elaborate silken tents. A different species, the eastern tent caterpillar, forms these more defined tents in branch crotches of cherry and other trees in the rose family.  For more detailed information about the forest tent caterpillar, please visit the U.S. Forest Service publication link at http://www.na.fs.fed.us/spfo/pubs/pest_al/ftc/ftc.htm.


Gypsy Moth (Lymantria dispar):

Adult Male Gypsy Moth	Adult Female Gypsy Moth

The gypsy moth was first introduced into the United States in 1869. Limited infestations of the gypsy moth have been reported in north, northeast and southeast Kentucky. The gypsy moth commonly attacks and eats the leaves (defoliates) of many major hardwood species, including oak, sweetgum and more than 300 other species of trees and shrubs. Annual defoliation of the tree by the moths can lead to death of the tree over a period of years. If the tree has no leaves, no food can be produced and the tree can starve to death or be weakened enough for other insects and diseases to attack and eventually kill it.

The female moths are flightless. They lay their eggs in masses on tree trunks and limbs, under houses, cars, campers, mobile homes and trailers. Because moving vehicles have been known to transport egg masses up to great distances, the gypsy moth is known as a "hitchhiker." For more information about the gypsy moth, please visit the U.S. Forest Service publication link at http://www.na.fs.fed.us/spfo/pubs/fidls/gypsymoth/gypsy.htm.

Hemlock Woolly Adelgid (Adelges tsugae):

Infestation of Hemlock Woolly Adelgid

The hemlock woolly adelgid is an aphid-like insect that originated in Japan. It is currently spreading from the northeastern to the southeastern United States. This insect attacks and kills eastern hemlocks of all ages, sizes and conditions. The hallmark of a woolly adelgid infestation is the presence of white, cottony masses on the underside of hemlock needles. The adelgids conceal themselves in these cotton-like masses. The adelgids are currently in Tennessee, Virginia, West Virginia and North Carolina.  Please contact the division if you suspect that your trees are infested with this insect.  For more detailed information about the hemlock woolly adelgid, please visit the U.S. Forest Service publication link at http://na.fs.fed.us/fhp/hwa/.

Southern Pine Beetle (Dendroctonus frontalis):

Adult Southern Pine Beetle	S-shaped egg galleries by a female Southern Pine Beetle

The southern pine beetle is a native insect and is one of the most serious threats to pine forests in Kentucky, as well as the entire southern United States. These small, hard-bodied beetles annually destroy millions of dollars of timber. Commonly attacked pine trees include Virginia, shortleaf, pitch and loblolly pines, although all pine species are vulnerable to beetle invasion. Beetles bore directly through the tree bark into the cambium layer, where beetles construct egg galleries.  As the eggs hatch, the  young beetles (larvae) bore throughout the cambium layer and disrupt the tree's water and nutrient flow system resulting in the tree's death.  During this activity, the tree's defense mechanism will produce pitch tubes resembling small kernels of popped corn in an attempt to oust the beetle. In the case of a minor infestation, the tree can be successful in its attempt to oust the beetle, but during the most recent outbreak in 1999-2002, the beetles were in such numbers that nearly 200,000 acres of pine forestlands in Kentucky were killed. 

Female beetles construct long, winding, s-shaped egg galleries between the bark and wood. These tunnels eventually girdle the tree and cause tree death. Trees infested with southern pine beetle demonstrate yellow to red foliage. Eventually, the needles drop off completely.  For more information about the southern pine beetle, please visit the U.S. Forest Service publication link at http://www.na.fs.fed.us/spfo/pubs/fidls/so_pine_beetle/so_pine.htm.