Friday, May 18, 2012

Tree Disease in Eastern Ontario ~ Emerald Ash Borer

Ash Tree Infected with EAB

Emerald Ash Borer
The Emerald Ash Borer is a green beetle native to Asia and is an highly invasive species to Ash trees in its host range.  Its natural range encompasses Russia, northern China, Japan and Korea; it was first discovered in Canton, Michigan in 2002, and it is suspected that it came via overseas shipping crates being delivered to Yazaki North America, an automative parts distributor.  Since its introduction into Canada in the 1990's, it has killed over 100 millions trees in its population growth and destruction, while threatening to kill over 7.5 BILLION Ash trees in North America.

While Green and Black Ash trees are their preferable host, there is no Ash tree that is resistant to the pursuit of the EAB, however, the Blue Ash does hold off the longest in its resistance.

The life cycle of an EAB can take up to two years in its completion, depending on the health of the tree, the deposit of the eggs and temperature.  Normally a female can lay up to 100 eggs in her two month life span and if one egg~laying female enters an Ash tree,   56% of these eggs are, on average, female; now, if they all lay eggs, within ten years you will have over 50 trillion Emerald Ash Borer's...enough to wipe out a nice sized forest of Ash trees.

The newly hatched larvae will burrow through the bark to the outer layer where they will feast on the new sapwood until the colder weather prevails, usually in the Fall.  In the Fall, they shape into a "J~shape" larvae while excavating pupal chambers where they wait for Spring.  In the Spring, they will eat their way out of the bark through D~shaped exit holes and are capable of flight upon emergence from the tree.  Smaller larvae may require the summer to continue their growth rate and the larger larvae will emerge during the Spring.

Become aware of your Ash trees as you notice the symptoms that usually prevail such devastation.  There will be a dieback of leaves in the upper third half of your tree upon onset and it progresses down over time.  They may be vertical splits in the tree bark, S~shaped channels found underneath the tree bark, D~shaped exit holes in the bark usually indicates a recent emergence, heavy woodpecker activity, especially in the winter months, epicormic shoots (water sprouts) that appear at the trees trunk and worm~like larvae that can grow up to an inch long found under the tree's bark.

A professional Arborist will know the proper requirements in which to effectively and safely remove or treat your Ash tree, if you have any questions, I would recommend calling one in your local area for an assessment.  As of today, only one treatment option has been approved by Canada and that is the use of TreeAzin, a biological insecticide, made from a natural product of Neem trees.  It is delivered to the tree via a special tree injection system and may only be administered by professionals.

In looking for the proper tree service company, individuals should keep in mind that a good tree care specialist will offer a wide range of services, including, pruning, removal, fertilizing, cabling/bracing, pest control and others, and not just tree removal.  NEVER use climbing spikes on healthy trees and NEVER remove a healthy tree...removal should ALWAYS be the last resort.


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