Category Archives: Forestry

Evaluating Storm-Damaged Forest Areas


Following our tropical storm, many landowners saw damage to trees in forests. We asked Dr. Moorhead to discuss this with us at this year’s Forestry & Wildlife program. At our first stop, we looked at damaged longleaf, and Dr. Moorhead gave an overview of assessing this damage. This is an exert from the publication “How to Evaluate and Manage Storm-Damaged Forest Areas“.

Storms ultimately cause damage by uprooting, wounding, bending, and breaking trees. Standing water following a hurricane can cause additional stress on trees and kill them. It’s good to have a plan to manage damaged timber.

  • Step 1 – Sketch or get aerial photograph of area ASAP.
  • Step 2 – Ground check damage to determine the need for salvage. This depends on location, amount of salvage and management objectives.

Type of Damage


This is the most common form of damage. In pine trees, this lowers the value since breakage is random and trees are cut to specific links. Hardwood trees are seldom killed by breakage. Breakage also permits entry of stain and decay fungi.

Recommendations: For pines, if 3 live limbs or less remain, the trees should be harvest as quickly as practical. For hardwoods, trees with broken tops or branches over 3 inches in diameter should be salvaged during next scheduled harvest.

Twisted Trunks

Logs from trees that have this damage may fall apart when sawn for lumber. Those pines may have pitch flow along the truck, but appear normal.

Recommendations: Trees with evidence of twist injury should be removed, since the problem will not disappear with time.

Root Damage

Get them out! These have to be salvaged quickly since stains, decays, secondary insects (Ips, powderpost, and ambrosia beetles) will further hurt the tree. Root-sprung pines will not die quickly, but will eventually incur invasions from blue stain fungi and bark beetles.

Major Wounds

This can occur from falling tops, other uprooted trees, and branch breakage. Pine trees with major wounds to the lower bole and large roots may be attacked by bark beetles. In hardwoods, woulds that do not penetrate more than 2 inches deep (into sapwood) and have less than 144 sq inches of surface area will have only localized stain, but little decay.

Recommendations: Trees with major wounds should pretty much be removed during next schedule harvest, or included in salvage operation.

Bent Trees

This is much of what we observed at our program Tuesday. Pine trees bent to the extent that cracks and resin flow occurs could be invaded by bark beetles and disease-causing organisms. Hardwoods are not usually attacked by insects or disease.

Recommendations: Trees under 15 feet in height usually straighten. Taller, more bent hardwoods need to be removed during salvage or next scheduled harvest. Many large, green, standing trees may not be usable for veneer poles or lumber since internal ring shake, splintering and separation of the wood fibers. Many times, the only external evidence of this damage is pitch or sap flow were the injury has broken the bark. It’s easy to overlook these signs.


Below is a table of choices for storm-damaged trees.


Recommended Choices for Storm-Damaged Trees

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2016 Forestry & Wildlife Program – Nov 1st


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October 13, 2016 · 2:11 PM

Tip Moths In Loblolly


This week, we looked 2-year-old loblolly showing dieback in the tips of branches. This turned out to be damage from tip moths, Rhycacionia genera. There are different species. Loblolly’s are susceptible to tip moths, especially young, less than 5 -6 feet tall. The damage is similar: the tips of terminals and laterals are killed as result of larval boring into base of the needles or buds, and then into the shoot itself.  They can also kill small trees.


Eggs are laid on the base of needles. When the eggs hatch, larvae bore into the needle sheaths and mine needles near their base. By midwummer, larvae move to buds and burrow in them. They stop feeding in August. They overwinter in the wound area. On the terminal of branches, we observed resin-coated webs, frass from worms, brown needles, and where worms were still present, you can see the tunnel in the branch. We also found a few caterpillars inside the stem. This is something we probably need to think about treating, though we are past effective treatments now. Here is a table from the book “Insects That Feed On Shrubs & Trees” showing species and hosts.



When it comes to treating, UGA Extension Forestry Specialist Dr. David Moorhead has a detailed guide to spray control. See the weather station locations in Table 4 to choose a site closest to your site for the spray date times.  There are numerous insecticides in the 2016 UGA Pest Control Handbook that are effective for control. These can be applied by fixed wing crop dusters or by ground rigs.

10 Bainbridge March 12-16 May 21-25 July 10-14 Aug 19-23



Resin soaked web from tip moth attack


Stem bored by tip moth


Tip moth larvae


Loblolly pine attacked by tip moth

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Pine Trees Bending?

Longleaf PIne

Here are some five year old long leaf pine trees where the terminals are bending or twisting awkwardly. This growth occurs when something physical breaks the terminal as they are young. Sometimes wind is to blame. There is also someone who noticed crows breaking terminals.


You’ll notice in the picture how much growth by the new terminals. Since these pines were planted on the edge of a yard, sort of residential situation, they are getting more fertilizer from grass. They are also likely in a really good spot. This extra growth also effects how these trees are bending. In this situation, you would not want to put any more fertilizer.

Mowing injury at the base causes pitch canker

Mowing injury at the base causes pitch canker

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Herbicide Injections, Directed, & Spot Sprays For Pine Release Hardwoods

ChinesePrivet (8)

This is the time of the year when we think about burning and herbicides use when we are trying to clean up hardwoods in pines. When we are preparing to burn and not enough fuel on the ground, we may need to treat individual trees. This past week, I’ve had discussions about wide-spaced injection techniques and basal bark techniques.

Wide-spaced Injection

When we have larger diameter trees, greater than 6″ diameter, we use this technique called hack and squirt. All you need is a small hatched and spray bottle. Imazapyr and triclopyr are commonly used for herbicides which are mixed with water. Depending on concentration of herbicide in solution is how many cuts we make in the tree. If 25% Arsenal AC or 50% Chopper is used, make 1 cut into the stem for each 3″ of tree diameter. (A 3″ diameter stem will receive 1 cut while a 6″ diameter stem will receive 2 cuts.) The cut goes right into the outer bark of the tree. You spray the solution into each cut.

Basal Bark

For hardwoods that are 6″ or less in diameter, we can use a herbicide mix with oil and spray the lower bark. This is called basal bark, thinline, or streamline treatment. We want a 20-30% of triclopyr and a 70-80% oil. You can mix this in a sprayer on a backpack or gallon sprayer. One of the questions we get is type of oil. Deisel fuel is commonly used as the oil, but the smell is not fun to deal with. Here is some information on oils and treatment specifications from UGA Extension Forester Dr. David Moorhead:


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Sawflies In Longleaf

Longleaf-Sawflies 014

One of the foliage feeding pests Dr. Moorhead discusses at our Forestry Meetings is the redheaded sawfly (Neodiprion lecontei (Fitch)) . It is actually a broadwaisted wasp which feeds on the needles of newly established pine trees. UGA Extension Forester Dr. David Moorhead said environmental conditions are good for sawflies right now.

Longleaf pine damage from redheaded pin sawfly

Longleaf pine damage from redheaded pine sawfly

This morning, we looked at a stand of 2 year old longleaf pines. The larvae of the sawflies chewed the needles back to the fascicle. There are many species of sawflies, and they are very selective in which pine species they feed. They are also treated the same way. They are very susceptible to different insecticides. Their infestations are generally localized, much like an Ips beetle. If the tree is not under stress, it can usually withstand this much damage. Some species have 1 gernation/year while others as much as 3 generations/year.


The redheaded pine sawfly has an olive green body with black stripes or a row of black spots on each side. And a large, black spot on the last body segment. Hosts of this species are loblolly, slash, and longleaf pines. They occur from Virginia to Florida and west to Arkansas and Texas.

Redheaded sawfly larvae

Redheaded sawfly larvae

Some of our insecticides used do not have a long residual – maybe 2 weeks (depending on rain and sunlight). It is best to treat each tree with active infestations. However, you may see some yellowing within the needles. The female adults have an ovipositor that is serrated which allows them to saw little slits in the needles were eggs are laid. This is how they get the name “sawflies.” Yellowing inside the needles are where females have laid eggs.

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Yellow on needles where sawfly eggs are laid

Chewing damage from redheaded sawfly

Chewing damage from redheaded sawfly

Sawfly damage on longleaf pine

Sawfly damage on longleaf pine

For more information visit Conifer Sawflies on the Center for Invasive Species website.

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Pine Needles Shedding?

Longleaf-NeedleShed (2)

Over the past month, we’ve been seeing different symptoms in loblolly and longleaf stands in the county. In some tree branches, we see inside needles turning brown and shedding where other trees, outside needles are turning yellow/brown. In either case, multiple issues can be associated with each symptom. What I want to show here is some longleaf needles where the inside is turning brown and shedding.

UGA Extension Forester Dr. David Moorhead says this is usually caused by a few different things. The symptoms can be associated with either a foliage disease like needle cast or an natural shedding of the older growth of needles. What we are seeing now is a natural shed. In a dry year, the tree will have one flush of growth in the season. With multiple wet years, the trees have put on more flushes of growth each year. This is resulting in a higher shedding this year. This is nothing we are concerned about. Basically, we have a higher component of older needles.

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