2017 Pine Beetles
Due to the wind damage from Hermine and Mathew along with drought conditions last year, Pine Beetle damage could pose a big threat to pine trees across South Georgia. Pine bark beetles can be a very serious problem when conditions are favorable and populations build rapidly to high levels. In outbreak years, these beetles can destroy thousands of acres of trees if they are not controlled. Therefore, it is important for all landowners with timber to keep up with beetle updates and to check their timber on a regular basis.
Drought stresses and weakens trees, making them more likely to be attacked by bark beetles. Under drought, trees do not receive enough water to perform their normal life processes, like converting sunlight to energy. Tree drought responses include leaf wilting, early leaf fall, dying tissue, shutting down roots, and changing chemical process within the tree. Many of these changes occur to conserve water and keep the tree from dying. Even as rainfall conditions return to normal, trees require time to fully recover from their drought response. So there can be a time-lag between increased rainfall and full tree health recovery. Unfortunately, this time-lag, wind damage and milder winter temperatures gives bark beetles more time to attack pine trees.
The three groups of pine beetles found in the southeast are the Black Turpentine Beetle,
Ips Beetles and the Southern Pine Beetle.
Black Turpentine Beetles are the largest of the southern pine bark beetles. They have rounded abdomens, are dark reddish brown-to-black and are about 1/4 inch long. Black turpentine beetles will usually attack trees in the lower eight feet of the trunk and often produce large pitch tubes (one inch diameter or larger) that will have a purplish color. These beetles feed just under the bark on the phloem tissue of the tree in groups called “feeding patches.” Trees that are not completely girdled may survive attacks from the black turpentine beetle.
Ips beetles vary in size by species. Adults are cylindrical in shape, usually are dark brown to black and range in length from 1/10 to 1/4 of an inch. The rear ends of Ips beetles look sunken or “scooped-out.” Ips beetles bore into the tree and feed just under the bark on the phloem tissue. They will attack trees at any height and produce small pitch tubes (less than ½ inch) that are a creamy white color. Ips beetles feed in a distinguishable pattern underneath the bark that looks like Y, H or I shaped galleries.
Southern Pine Beetle adults are about 1/8 of an inch in length and have rounded rear-ends. They will usually attack trees in the mid-trunk to the lower crown and feed just under the bark on the phloem tissue. Their pitch tubes are small (less than ½ inch) and are usually a creamy white color. Southern pine beetles feed in a distinguishable pattern underneath the bark that looks like S shaped galleries.
Southern pine beetle is the most destructive of the pine bark beetles. SPB often build up very large populations and kill from several dozen to many thousands of trees in an area. These attacks usually move in one direction over time as successive generations move to other trees. A corresponding progression in color of the needles on infested trees can be observed, resulting in the “beetle spots” associated with SPB attack sequence.
Isp beetles and black turpentine beetles are present virtually every year but seldom kill large numbers of trees in one area. However, under certain conditions, both the black turpentine beetle and the Ips beetle can reach outbreak levels and cause widespread damage.
Because of the wind damageand drought stress to pine trees in South Georgia, all timber producers will need to be on high alert and check their pines stands for beetle damage on a regular basis. Although pine bark beetles can be extremely destructive, landowners can take steps to manage them and reduce losses. Keep trees growing rapidly and promptly remove damaged trees. Trees damaged by lighting, wind, fire or harvesting equipment causes stress which make the trees more susceptible to beetle damage. Know how to identify possible bark beetle infestations in the early stages and treat the infestations if needed. Finally, keep up with beetle numbers through the Georgia Forestry Commission and other landowners. I you need more information or help with identifying or treating pine bark beetles, give us a call at the UGA Extension Office here in Wayne County at 427-5965.