"What is next?" one might ask when watching the trees decline in their neighbourhood. After years of diseases and insect infestations in trees, people are worried for their urban environment and its well-being. Naturally so, since trees are a necessity in the production of oxygen, clean air and comfortable climate. With Elm Bark Beetles, dutch Elm Disease, Asian Longhorned Beetle and now Emerald Ash Borer, much of our urban forests are in danger. Many of these pests are being sought out and monitored by the Canadian Food Inspection Agency and other Research Centres.
Emerald Ash Borer (EAB) is the latest infestation found in Ontario. It is believed to have first been found in the Western Ontario Regions, in the vicinity of Sarnia and Windsor. Recently there have been confirmations of infestation in the Greater Hamilton, Toronto, and Burlington area. The key to some control of this pest is to be able to properly identify some of the symptoms and notify key people in the industry to help advise you in the correct treatment.
People ask "what do I look for? what are the signs? how big is the insect? who can I call? First of all we must be able to identify what species the tree is, and the host of this particular insect is obviously Ash (Fraxinus). This is a large portion of both our natural wood lots and urban forest setting. Once you have determined that the tree in decline is an Ash tree, you can take it to the next step. Understanding the insect life stages and size is very important. The EAB has four life stages: egg, larva, pupa and adult. The Egg is flat, oval in shape and about 0.6-1mm in size, reddish brown and hidden in bark plates or striations. The Larva, when fully grown can be as large as 32mm long, and creamy white to lighter green with a small brown head. They feed between the sapwood and bark, throughout the entire tree. It is in this stage that most damage is done, with numbers into the thousands in a single tree, the EAB can quickly cut off the flow of sap and nutrients through the tree leading to death. As the larva matures it becomes J-shaped and is heading into the pupa stage (in September), where the transformation into insect begins. As the EAB develops the pupa is found under the bark from April until the middle of July. In the adult stage it has a shiny emerald green colour and large black golden eyes. the body can be 4mm wide and 8mm long and are detectible from early July to August. This is when they feed on the leaves, mate and begin the cycle over again.
Signs and Symptoms are the physical damage the insects are doing to the trees. They consist of visible and hidden clues which can often be mis-diagnosed. Other pests, winter stress, and other visible decline can happen without the infestation of EAB and appear very similar so it is very important to commission a knowledgeable Arborist, or Forester to help investigate the trees.
Some signs and Symptoms; Yellowing of the leaves, dieback of the top half of the tree, sudden large dead branches, separation of bark from the wood, galleries under the bark, borer holes in the shape of a D 3.5-4.5mm wide, leaf damage, water sprouts (suckers or epicormic shoots), and heavy seed production.
The treatment is available under an emergency registration and is very friendly to the environment however quite expensive. it is an injection which can be done into the tree, it involves no spraying and is very effective done prior to or early in the life cycle.
If these symptoms are found please contact us for assistance.More Articles ›