Bark beetles threaten area pine tree population

Published 8:45 am Wednesday, April 6, 2011

by Terry Godwin

You may have noticed an increase in the amount of dead pine trees throughout southeastern Virginia and northeast North Carolina.

It appears as though extremely dry weather last fall, combined with a 10-year cycle of bark beetle infestations, may be setting us up for some significant timber losses. The last outbreak across the South was in 1995 where bark beetles killed 20 million acres of timber.

There are ways to limit losses and possibly prevent them all together. This article will discuss techniques to identify the different types of bark beetles, how to deal with them if you have them, and how to prepare your pine timber to limit losses.

The two main species that attack southern yellow pines are the southern pine beetle and the Ips Engraver Beetle. Both beetles have the ability to make the needles of the trees to turn brown and kill the tree.

The southern pine beetle is the species that causes the most damage and usually spreads the fastest. The beetles are usually found in the lower trunk of the tree. The first signs of an attack will be brown needle and pitch tubes on the trunk of the tree.

As the beetles bore into the wood, the tree will push out pitch to defend itself, thus causing a white pitch tube to appear. Also once the southern pine beetle is in the tree, they tend to bore “S” shaped egg galleries that can be seen on the inside of the bark.

The Isp Engraver Beetle will attack all parts of the trees, but the pitch tubes tend to be brown and the egg galleries tend to be in a “H” or “Y” pattern.

Pine bark beetles are most successful in killing stressed and weak trees but can kill healthy trees as well. Stresses are usually associated with drought, disease and overstocked pine stands.

We can’t do much about drought, but we can make sure that we keep stands thinned and growing vigorously. Mature stands are also susceptible and need to be checked periodically.

If a stand is attacked, the control method is to cut a buffer area around the infestation in the directions that the beetles are spreading. Ideally this would be part of a logging operation, but it is just as effective if the wood is cut and left.

It is very important to stop the spread of the beetles before they kill a larger portion of the timber stand. For pre-commercial sized timber or hard to get to areas, it is best to cut the timber down and leave it at the site. These trees should be felled toward the center of the infestation.

It is important that you, your forestry consultant, or a forester from the state department of forestry walk through your pine stands and look for pine bark beetle activity. Foresters will have the knowledge on how to identify the type of beetles effecting the stand and determine how best to control it.

We recommend having your forest thinned as soon as possible to maintain a healthy and vigorously growing stand. If you see a problem, take action immediately to prevent losses.

WM. TERRY GODWIN is a consulting forester in Franklin and can be reached at or 556-5271.