Decreasing The Potential Spread Of Disease And Insect Infestation
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 carry and spread the DED fungus to other elm trees.
A similar scenario plays out with the numbers of beetles that can be produced in standing and cut wood of pine and spruce trees. 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.
Methods of controlling the spread of contamination
It is urgent that infested wood be disposed of from the following trees to prevent the spread of contamination to other trees in your neighborhood. Recommended disposal methods include, chipping the wood and bark, burning, burying, or removing all bark from wood and stump. This will help prevent infestations from spreading.
| 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 |
For more information on prevention and management please contact your Rainbow Treecare Arborist.
An integrated approach
When caring for urban trees it is important to make a complete evaluation of all environmental conditions to accurately diagnose all stress factors and prescribe care based on specific circumstances. This prescriptive care will help your tree meet its full potential.
