Beetle Life Cycle

• The tiny brownish-black beetles tunnel through the tree's wood. The female beetle bores into the trunk and large branches to excavate cavities to lay her eggs. A female will deposit up to 60 eggs per cavity and plug up the hole with excrement. The eggs hatch in approximately 15 days, and the larvae begin to burrow into the tree's wood. The extensive tunnel system in the phloem of the tree disrupts the tree's ability to absorb nutrients. In northern areas of the United States, the beetles produce one generation, while in southern regions they will have two generations.
  
  

Damage Appearance

• Infected trees, on internal inspection, display centipede-like galleries just beneath the bark. An extensive infestation will girdle the tree and result in its eventual death. The foliage of trees under attack from hickory beetles turns yellow and eventually red. As they die, the leaves turn brown and fall off. During the fall and winter, infected trees bear small entrance holes along the trunk and branches. Adults emerging from the trees in summer leave numerous exit holes, giving the bark a buckshot appearance. The presence of woodpecker drilling also indicates the presence of bark beetles. Trees weakened by the hickory beetle often contract the fungus Ceratocystis smalleyi. The fungus causes cankers to develop underneath the bark on the tree's trunk.
  
  

Prevention

• Maintaining a tree's health helps prevent hickory beetle infestations. Healthy trees rarely suffer a severe attack from the pests. Regularly prune, fertilize and water the tree to keep it strong enough to withstand pests. Trees weakened by stress are most susceptible to debilitating attacks by bark beetles. Stress conditions include drought, fire damage, pollution and overcrowded stands.
  
  

Control

• Spray ornamental trees with an insecticide in early July to prevent and control beetle infestations. In larger stands, cut down infested trees during the winter months while the beetles are inactive inside the trees. Burn or chip the wood to destroy the beetles and their larvae. Submerging cut trees in water also kills the pests. Peeling back the bark of a tree at sites of infestation and spraying the area with an insecticide in the spring before the adult beetles emerge can help control the beetles.