Decreasing The Potential For Infestation

How to prevent the spread of tree diseases and insects

When trees die due to disease or insect infestation it is imperative that the infected materials be removed from the site or destroyed.  Infested trunk and branch tissues can harbor the disease pathogens, bark beetles, and other boring insects that can infest other trees in the neighborhood and continue the pattern of decline throughout the region.  This is especially the case with Dutch Elm Disease (DED) infected elm trees and with pine and spruce bark beetles.  Elm bark beetles will infest recently cut wood with the bark still attached, including the root crown tissue left after a tree removal.  If the tree was diagnosed with DED, this "brood" material can produce upwards of 500 beetles per foot of wood tissue.  Each of these beetles will also be carrying the DED fungus to other trees. 

With bark beetle infestations on pine and spruce trees, the same scenario plays out with the numbers of beetles that can be produced in the cut wood.  With conifer bark beetles it is the beetles themselves that cause the damage.  A tree in a state of decline is unable to produce enough resin to encapsulate bark beetle larvae.  When this situation occurs, the trees become targets for the beetles.  Once an attack occurs, the beetles create a scent (pheromone) that attracts additional beetles.  By increasing the attack rate on the tree, the insect can overwhelm the trees limited defenses.  When beetle populations build up to significant levels, they may begin attacking healthy trees.  That is why it is urgent that infested trees and wood be removed, chipped, burned, buried or debarked to prevent infestations from spreading. 

Please dispose of infested wood from the following trees to prevent their spread to other trees in your neighborhood.

Tree Species	Infection and/or Infestation
Red Oak / Pin Oak	Oak Wilt, Two-lined Chestnut Borer
Bur/White Oak	Two-lined Chestnut Borer
Elm	Dutch Elm Disease, Elm Bark Beetles
Pine/Spruce	Bark Beetles
Birch	Bronze Birch Borer

 

 

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