Withering and death of trees leaves followed by death of twigs and branches are the first signs of Seiridium Canker. You will notice a reddish tinge on the bark or a darkened bark with resin spilling from open cankers. This form of canker is commonly found in Leyland Cypress trees, but can be found in others. It is spread from branch to branch or tree to tree through irrigation and rain splash. Seiridium Canker affects trees weakened by extreme heat and drought conditions. There are no chemical treatments for Seiridium Canker, but a Certified Arborist can diagnose affected limbs and can prune to remove the infection, removal of the tree may be necessary in severe cases.
The first noticeable symptom of this disease, is yellowing and wilting of leaves due to stress on the tree. Hypoxylon Canker causes fungal mats, or stroma, to develop beneath the bark. The stroma puts pressure on the bark causing it to slough off, the exposed stroma will be hard, tan to silver gray on the outer layer and black within. Because Hypoxylon Cankers are opportunists, stressed trees in Urban Environments like Atlanta are especially susceptible. Stress from heat, drought, wounds, root injury from construction and soil compaction make trees a target for this disease. Prevention of this disease is easy with regular visits from a Certified Arborist who can ensure proper irrigation and fertilization as well as recognizing risks and hazardous branches.
Armillaria Root Rot
Armillaria Root disease is characterized by crown dieback, growth reduction, premature leaf drop, or death of the tree. This fungi inhabits the roots of the tree and detection is difficult unless characteristic honey brown to reddish mushrooms are produced at the base of the tree. The fungus will break down the lignin and cellulose in the tree causing the wood to become spongy, removing the bark will expose the white mycelial rhizomorphs of the fungus that grows between the wood and the bark. Favorable conditions for Armillaria are produced when the soil remains too wet. Healthy trees can produce resin and limit the spread of the fungus by sealing off infected areas, but stressed trees are unable to heal themselves. The best method to treat fungus is prevention, call a Certified Arborist to create a maintenance plan for tree vigor.
Ambrosia Beetles are opportunists, they attack trees that are in decline or have dead tissue. The female beetle bores into the dead tissue of a tree in the Spring and deposits her eggs. With this she also begins to spread a deposit of ambrosia fungus which grows in the xylem tissue of the tree providing nutrients for the beetles. This fungus attacks the tree and eventually leads to the decline of the tree. There is no treatment for an Ambrosia Beetle attack once it has been identified, the fungus cannot be eliminated. To prevent Ambrosia Beetles in at risk trees (Crepe Myrtle, Redbud, Dogwood, Cheery, etc.), a Certified Arborist may apply an insecticide to deter beetles from landing there.
Pine Beetles typically attack Pine trees that are dying or in decline, but if an infestation occurs the overwhelming number of beetles may attack a healthy tree. This insect bores into the inner bark of Pine trees and feeds on the phloem tissue, causing large resin masses to form on the outer bark of the tree. They excavate serpentine galleries throughout the inner tissues of the tree and can cause the eventual death of the tree. Pine Beetles also carry blue-stain fungi, this fungus colonizes xylem tissue and blocks water flow. There is no treatment for Pine Beetles, but with proper maintenance, irrigation, and pruning trees should remain healthy. A Certified Arborist can apply an insecticide to prevent infestation.
Scale Insects are small pests which attack evergreen and deciduous plants. They are very small and hard to notice but can occur on leaves, twigs, and trunks. Scale Insects feed on plant nectar or sap, draining the plant of vital fluids. They produce a sticky, waxy substance known as “honeydew” on the plants they inhabit which can cause a nuisance for anything below the infected tree. Proper fertilization and pruning can keep trees protected from Scale Insects. When they infest a tree, leaf and needle stunting and yellowing and branch dieback are noticeable. If the infestation is severe plant death may occur. Because Scale weaken the tree through depriving it of fluid, the tree becomes susceptible to boring insects and other environmental hazards.
In Japan, Japanese Beetles are controlled by natural predators. In the United States, Japanese Beetles are a predator for nearly 300 species of trees. These beetles skeletonize the trees they infect, meaning they consume the leaves between the veins giving them a skeleton-like appearance. They are most common in June and will devour leaves, flowers, and overripe fruit. This prevents the plant from acquiring nutrients through photosynthesis and can severely damage the plant. A Certified Arborist can apply an insecticide to your plants to kill a beetle infestation, apply a soil insecticide to kill larvae and grubs, or spray on susceptible plants as a preventative measure. There a beetle traps available for purchase, but a recent study shows that while these traps can catch several thousand beetles a day, they also attract the insects to trap causing more damage to trees along the flight path.
Aphids, also known as plantlice, feed in dense groups on leaves, stems, and other soft tissues depleting plants of fluids. There are several different species of Aphids, and in a moderate amount do no damage to trees. In large quantities, Aphids can turn leaves yellow and stunt growth. Some Aphids inject a toxin into plants when they feed causing decline of tree health. Very infrequently is chemical control of an Aphid infestation necessary, call an arborist to have your tree evaluated and determine which course of action to take.