Conifer Bark Beetles

Several species of bark beetle including Southern Pine Beetle, Black Turpentine Beetle, Mountain Pine Beetle, Western Pine Beetle (all Dendroctonus species), Ips Engraver Beetle, and Spruce Beetle are known to attack and kill conifers such as pines and/or spruce.

These beetles bore into the tree’s cambium in large groups and disrupt nutrient and water movement, thus killing the tree. Several of these species also introduce a fungus, known as blue stain, which may kill a tree by clogging its vascular system.

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  • Common Symptoms
    • Most of these beetles will attack both stressed (drought, nutrient deficient, excess moisture) as well as healthy conifers. Cream to red colored pitch tubes will be present in the lower bole of the tree. Crowns of individually attacked trees will fade from green to yellow to red, followed by tree death over several weeks. Most of these beetles carry a fungus that serves as a food base for young larvae. The introduced fungus inhibits water transport and hastens tree mortality.

    • A trunk injection of TREE-äge®, TREE-äge® G4, and TREE-age® R10 will provide up to two years of protection from bark beetle damage. Preventive treatment is best, as trees with existing beetle infestations are unlikely to survive. In areas where beetles carry the blue stain fungus, it is recommended that a systemic fungicide such as Propizol® be added as a sequential treatment to eliminate additional stress from the fungus.

    When To Treat
    • Effective injection treatment is favored by a full canopy (i.e., leaves) and healthy vascular system. Once these tissues are compromised by arthropod damage (larval galleries, defoliation, leaf mining, etc.) an effective and uniform application of TREE-äge may be difficult to achieve and subsequent control may be poor. Optimally, treatment should be made preventively at least 2 to 3 weeks before arthropods historically infest the host tree. As a result of systemic movement and longevity of TREE-äge in trees, this interval may be extended much earlier to 6 months should tree dormancy, adverse weather, management, asynchronous life cycle of pests, etc., allow earlier application timing.

      TREE-äge may also be effective as a remedial treatment against some pests, such as those with slower development or if multiple life stages are susceptible to TREE-äge . Pests that attack the stem and branches such as bark beetles and clearwing borers may disrupt vascular tissue resulting in poor distribution in an infested tree. This includes the initial larval stages of pests, such as bark beetles and clearwing borers, that attack the stem and branches, which may disrupt vascular tissue resulting in poor distribution of the product in an infested tree. However, control may be achieved if larvae come into contact or feed on TREE-äge treated tissues.

    What To Expect After Treatment
    • You can expect TREE-äge to be systemically distributed throughout the treated tree and protect the tree from the pest for up to 2 years.

    References And Photo Credits
    • Photo Credits

      Small Fir Bark Beetle: Daniel Adam, Office National des Forêts,
      Ips Engraver Beetle: G. Keith Douce, University of Georgia,
      Black Turpentine Beetle: USDA Forest Service – Region 8 – Southern , USDA Forest Service,

      Damage: Gyorgy Csoka, Hungary Forest Research Institute,

©2019 Arborjet, Inc. Important: Always read and follow label instructions. Some crop protection products may not be registered for sale or use in all states or counties. Please check with your state or local extension service to ensure registration status. TREE-äge® Insecticide is a Restricted Use Pesticide and must only be sold to and used by a state certified applicator or by persons under their direct supervision.  TREE-äge® is a registered trademark of Arborjet, Inc.