U.S. Forest Service officials at the Cherokee National Forest (Forest) say visitors to the Forest may see areas of dead foliage on some trees. Leaves are dying and turning brown as a result of damage caused by the yellow-poplar weevil. The insect primarily impacts yellow-poplar trees, but can also feed on other species in the magnolia family and sassafras trees.
Adult weevils begin feeding on leaf and bud tissue in April and May. They mate, lay eggs, and newly pupated adult weevils emerge in late spring/early summer. The newly emerged adults may cause extensive damage to leaf tissue. As a result, the leaves die and turn brown. By mid-July the weevils will drop to the ground and remain inactive until the following spring.
When abundant, the weevils destroy the leaves and buds of terminal and upper branches and in extreme cases may defoliate entire trees. Growth of trees may be slowed and tree form may also be affected. Most healthy poplar trees will be able to withstand the defoliation caused by the weevils, but they may suffer aesthetic damage.
The yellow poplar weevil is native to the eastern U.S. The last recorded significant outbreak has not been recorded since the late 1960’s. Adult weevils are about 1/10 of an inch long and are a dark brown or black in color. There are at least five recorded parasitic wasp species that are known to prey on the weevils and their larva. Frost in late spring also reduces the size of weevil populations.
Foliage destruction temporarily reduces the aesthetic values of yellow-poplar trees and sometimes reductions in growth may be experienced. However, most healthy trees are able to withstand an infestation. The outbreak should subside on its own.