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| BRONZE BIRCH BORER |
Description
European White Birch and its cut-leaf variety are most susceptible. The Paper of Canoe, Yellow and Grey are also attacked to a lesser degree. River, Heritage and Monarch Birch are considered to be resistant and are suggested for any new plantings in your landscape.The first sign of borer attack is usually a die-back of the uppermost branches, flowed by a gradual decline and eventual death of the entire tree in 2 to 3 years. Vein-like ridges or swollen bands will probably be present in the bark of the trunk and branches. The presence of D shaped adult emerges holes, roughly the size of a pencil lead in the trunk, is a positive sign of borer activity. The adult borer lays its eggs in bark crevices or beneath loose bark flakes during the months of June, July, and early August. However, areas of mechanical or other injury appear to be the most attractive egg laying sites, so care should be taken when using lawn mowers or other tools that may damage tree bark. Egg hatch occurs approximately two weeks after being deposited, and the young larvae bore into the tree to begin feeding on the inner bark (Phloem) and Cambium layer. The Phloem and Cambium are the water and nutrient conducting Life Blood of the tree. Trees under stress are more susceptible to borer attack that trees in a vigorous state of growth. Stressed tress emit a chemical scent called phearmones. This scent attracts many different species of borers, including Bronze Birch Borer. Therefore, it is imperative that susceptible trees be an a fertilization program to maintain the overall health and vigor of the plant. It is also important that trees receive frequent deep watering during dry periods (when rainfall is below 1 per week). Mulch helps retain moisture during these times as well as moderate root temperatures. Mulching also eliminates the need to use lawn mowers or weed eaters near the base of the tree, reducing damage to the bark. |
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How
to Treat
IN ORDER TO GIVE YOUR BIRCH TREES THE BEST POSSIBLE PROTECTION, a two part program is required. The first part is a spray program targeted at the Birch Leaf Miner, which attacks the foliage and weakens the tree, thus making it far more susceptible to borer invasion. The second part is a bark spray that controls egg laying adults and newly hatching larvae before they enter the bark.Trees which are severely infected with existing borer problems must be initially trunk injected with Mauget Bidrin & Stemix injector units. Trunk injecting places the necessary control within the trees vascular system. As the borer larvae feed, they ingest the Bidrin insecticide and are killed in the tree. Mauget injections are very effective in controlling existing borer problems, killing over 95% of the borers inhabiting the tree. Within 2 years after this, annual spraying and maintenance can prevent reinfestation. Given the nature of this pest , and the speed at which it can kill a seemingly healthy tree, its important that the homeowner do his part in regards to watering, mulching and minimizing trunk injury. Working together, the homeowner and arborist can keep these beautiful and valuable members of your landscape disease and pest free. |
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