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					Major Pests of WA Forests
    • Weakens trees and
      predisposes them to
      other problems
             Root diseases
• Affect ability of plant to absorb water and
• Symptoms – What you see above ground
• Signs – Actual damage or disease
  organism seen below ground
Annosus root rot
        • Crown yellowing and thinning

        • Distress crops of cones

        • Trees killed in disease centers

        • Wind thrown trees

        • Conks on declining live trees,
          dead trees, and stumps

        • Annual rings separate with pits
          on one side of sheets
Armillaria root rot
          • Occurrence of white
            mycelial fans under the
            bark of roots and lower
            stems is diagnostic.
            Advanced decay is
            yellow, stringy, and
            Rhizomorphs (black or
            brown shoe string-like
            structures) may be found
            under bark, and golden-
            colored mushrooms of
            the pathogen often
            appear around the bases
            of infected trees in fall
         Armillaria root rot
• Rhizomorphs
          Armillaria root rot
• Resins oozing from tree
Black Stain root rot
          • Occurrence of dark
            brown to purple-black
            stain in the sapwood
            of infected roots and
            lower stems is
          • Host is mostly
            Douglas fir
           Laminated root rot
• Rot on bark       • Incipient decay appears
                      as a reddish stain that is
                      crescent-shaped or semi-
                      circular in cross section.
                      Advanced decay is
                      laminated with pitting on
                      both sides of the layers,
                      and diagnostic reddish-
                      brown to pinkish whiskery
                      setal hyphae occurring
                      between the laminae
Laminated root rot
Sudden Oak death
        • A pathogen that has killed
          thousands of oaks in
          coastal central California
          has recently been found
          in southwestern Oregon.
          Are we concerned?
        • Investigations thus far
          suggest that P. ramorum
          invades tree hosts
          through the bark on
          stems and limbs. Oozing
          cankers result
Brown cubical butt rot
           • The mushroom-like fruiting
             bodies are the most reliable
             signs of infection. They are
             produced annually on the
             ground near the bases of
             infected trees. Occasionally,
             they occur on the stem, usually
             within 3 1/3m (10 ft) of the
             ground. They are velvety in
             texture and reddish, greenish,
             or yellow-brown with yellow
             margins. As they age, they
             become dark brown, brittle and
             resemble cow-pies
Brown cubical butt rot
           • P. schweinitzii causes
             severe root and butt
             decay of older trees.
             Wind breakage above
             the groundline is
             more common than
Phomopsis Canker of Douglas fir
                • causes stem cankers,
                  leader and branch
                  dieback in trees from
                  seedling to pole size.
                • The disease is
                  troublesome in young
                  plantations and in
                  natural regeneration,
                  especially following
                  drought conditions in
                  the growing period
Western gall rust
         • Most common
           disease of lodgepole
         • Large pear shaped
           galls on tree branch
         White pine blister rust
• This disease does not      • Resin flow from
  affect species outside       branch and trunk on
  of the white (5-             advanced infections
  needle) pine group         • Alternate host – Ribes
• Often infections kill
  the branch, resulting
  in bright red "flags" in
  the crown
White Pine Blister rust
White pine blister rust
White pine blister rust
       White pine blister rust
• Flagging of branches
Phytophthora root rots of seedlings
                  • Fungus causes
                    damping off in many
                    nursery stock
                  • Cold, wet conditions
                    promote the fungus
                  • Poor water drainage
                    in the soils is a
              Bark Beetles
• Aggregating pheromones allow bark
  beetle populations to fully occupy
  ephemeral host material and, in the case
  of those species attacking live trees, to
  overcome the defenses of the host
  through mass attacks. Another adaptation
  is the close association of the insects with
  staining and wood decay fungi that the
  bark beetles introduce into the host plant
                Bark beetles
• Mountain Pine Beetle    • Most conifer species
  Western Pine Beetle       have at least one
  Red Turpentine Beetle     associated bark beetle
  Pine Engraver Beetles     that is capable of killing
  Douglas-fir Beetle        the tree under the right
  Fir Engraver              conditions. Those bark
  Spruce Beetle             beetles that infest live
  Ambrosia Beetles          trees are fairly
  Flatheaded Borers         opportunistic and usually
  Roundheaded Borers        require their hosts to be
                            under some form of
                            physiological stress for
                            colonization to be
    Mountain pine beetle
•    Adult and grub   •   Egg galleries long and straight,
      (larva)             with the grain (vertical)

                      •   Larval galleries at 90 angle from
                          egg gallery

                      •   Yellow pitch tubes on trunk

                      •   Red boring dust in bark crevices

                      •   Pitch streamers on trunk

                      •   Foliage discolored
                      •   Adult beetles prefer to attack
                          large-diameter trees. Bigger trees
                          provide higher quality food and
                          larval habitat
    More mountain pine beetle
• Damaged forest, view      • Galleries and pitch
  from plane or satellite                    tubes
Western Pine Beetle

          • Egg galleries winding,
            branched, crossing

          • Small yellow pitch tubes

          • Red boring dust in bark
            crevices and at base of tree

          • Larval galleries short, entering

          • Large patches of bark often
            removed by woodpeckers

          • Foliage discolored
Criss-crosssing pattern of galleries
      of western pine beetle
    More western pine beetle
• Stand mortality
Red Turpentine Beetle

           • The most obvious sign of
             RTB attack is large (up to
             2 inches across) reddish
             globules of pitch (pitch
             tubes) at the point of
           • These are located on the
             lower part of the tree
             trunk and on the root
           • Galleries of the insect are
             irregular and packed with
Pine Engraver Beetles

           • Galleries have a central nuptial
             chamber from which 2-3 egg
             galleries radiate

           • Galleries free from frass

           • Yellow or reddish boring dust
             in bark crevices or on ground

           • Foliage discoloration

           • Top-killed trees

           • Insects small, dark beetles 1/8
             to 1/6" in length
              Pine engraver
• Ips – note the back   • Pitch tubes
  elytra spines
Douglas-fir Beetle

         • Galleries straight, vertical,
           packed with frass
           (waste material)
         • Larval galleries fanning out
           from egg gallery

         • Red or yellow boring dust in
           bark crevices or at base of tree

         • No pitch tube

         • Resin streamers on upper bole

         • Foliage discolored
Fir Engraver

      • Reddish-brown or white boring
        dust in bark crevices or at base
        of tree

      • Egg galleries straight, across
        the grain (horizontal)

      • Larval galleries at 90 from the
        egg gallery

      • Galleries deeply etch sapwood

      • Galleries free of frass

      • Foliage may thin, yellow, or
More fir engraver
Spruce Beetle

       • Hosts in Southwest Oregon:
         Engelmann and Sitka spruce
       • On standing trees, the first sign
         of spruce beetle infestation is
         reddish-brown boring dust
         accumulating at the beetle's
         entrance holes, in bark
         crevices, and on the ground
         around the trunk of infested
         trees. Masses of pitch may
         accumulate around the
         entrance sites. These signs
         are most visible during the
         summer of attack and become
         less noticeable the following
Ambrosia Beetles

        • Adults bore directly into the
          sapwood of their hosts, each
          producing a pile of fine white
          boring dust at the point of
          entry. As they construct their
          galleries, the beetles introduce
          a fungus that grows inside the
          gallery and in the adjacent
          wood. The black stain
          produced by this fungus
          around the insect's gallery is a
          good diagnostic tool for
          recognizing infestation by
          ambrosia beetles.
Flatheaded Borers

         • Most attack weakened,
           dead, and recently felled
           trees. Galleries in the
           wood can affect
         • Since flatheaded borers
           are generally associated
           with dead or severely
           damaged trees, they are
           usually not the objects of
           direct management
Roundheaded Borers
         • They introduce wood
           decay fungi into the wood
           and hasten the rate of
           decay. Their tunnels can
           lead to a significant loss
           in value in logs that are to
           be processed for lumber
         • The vast majority of
           western longhorned
           borers are insects that
           infest the wood of
           recently dead trees
• Western spruce        • Consume foliage
• Douglas Fir Tussock
• Gypsy Moth
Western Spruce budworm
           • Foliage with scorched or
             blighted appearance at tips

           • Needles bound together with
             webbing at branch tips

           • Defoliation caused by 1" or
             smaller caterpillars

           • Caterpillars brown with green
             markings, white spots on
             sides, not hairy

           • Top kill or death following
Douglas Fir Tussock Moth
            • Foliage appears scorched
              or off-color

            • Defoliation from top down
              and from outside in

            • Thin crowns and top kill

            • Defoliation from hairy
              caterpillar up to 1" in
     Douglas fir Tussock moth
• Female is flightless   • Loose webbing
Gypsy Moth
     • Male dark brown
     • Introduced pest, wide
       range of hosts
           Pheremone traps
• Detect insect
• Spray of infested area
• Sex attractant
• It is a plant, with roots
  stems and leaves
• Depends on plant for
  water, minerals, and
  some sugars
• When tree dies it dies
• The plant spreads primarily by
  seed. The berry-like fruits ripen
  in the late summer or fall and
  burst, shooting their sticky
  seeds distances up to 50 feet.
  The seeds adhere to needles,
  twigs, branches and trunks and
  germinate the following spring.
  Infection of the host occurs
  when the root-like structure
  from germinated seed
  successfully penetrates the
More mistletoe

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