Here are some longleaf pines being cut down on a plantation that are having some issues. The needles at the tops of the trees have turned brown and died back. It is a classic sign of Ips Engraver beetles. When a tree is struck by lightening, more often than not, Ips beetles will fly in and attack the tree. Ips will usually hit a few trees and then leave the area. Ips along with Southern Pine beetles induce blue-stain fungus which quickly kills the tree. The initial problem was that we were not seeing signs of Ips beetles.
Signs of beetle attack are pitch tubes on the bark/branches, sawdust at the bottom of the trees, or galleries (beetle tunnels) inside the bark. We inspected the few trees that had not been cut down and trees that had just been cut down. (SPB enter the middle and top of the trees. Ips will enter the tree at any spot. Only Black Turpentine beetles enter the bottom of the tree.) Photo to the left is sawdust left from secondary Ambrosia beetles.
Without the signs of any primary beetles, we considered disease. These trees had actually showed this decline since November. Since Ips beetles do induce blue-stain fungi, this would kill a tree very fast as fungi clog the vascular system stopping water movement up the tree. We are in a hot spot for Annosum root rot in our area since we have well-0drained sandy soils. However, annosum rarely causes trouble longleaf. It is devastating on slash and loblolly. The last thinning here was done 15 years ago, and annosum generally infects following a thinning.
UGA Extension Forestry Specialist Dr. David Moorhead pointed out that the tops of these trees are flattened out (top photo). This means these longleafs have ceased terminal growth and only growing laterally. They are at the age were they naturally will develop Red Heart. Red heart is normally confirmed when the tree is cut down and we see large decay inside the trunk. Sapwood here still looks good. The best management is to salvage declining trees without damaging other trees, and maintain overall forest health.