Tree Disease No. 1

1
Tree Disease No. 1

• Symptoms
• The symptoms rapidly spread, usually one branch
  at a time, to progressively larger branches and
  eventually the entire tree.

2
Tree Disease No. 1

• Symptoms
• Symptomatic branches often contain brown
  discoloration or streak in the outer xylem.
  This type of discoloration is a common symptom of
  vascular wilt diseases caused by fungi.

3
Tree Disease No. 1

• Signs
• In dead trees or trees infected more than one
  season, egg galleries of bark beetles can be
  found beneath recently killed bark.

4
Tree Disease No. 1

• Signs
• Two species of elm bark beetles are important
  vectors of this pathogen
• European elm bark beetle
• (Scolytus multistriatus)
• Native elm bark beetle
• (Hylurgopinus rufipes)

5
Tree Disease No. 1

• Signs
• Another species of elm bark beetle may be an
  important vector of this pathogen
• Banded elm bark beetle
• (Scolytus schevyrewi)