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Walnut

Other Pests and Damage You May See—Late Spring

On this page
  • Phytophthora root and crown rot cankers
  • Ground squirrel burrows
  • Tree squirrel damage
  • Crown gall
  • Fall webworm tents

Names link to more information on identification and management.

Click on photos to enlarge

Phytophthora root and crown rot
Phytophthora root and crown rot cankers
Identification tip: To confirm the presence of Phytophthora crown rot, cut away the outer bark and look for a canker that has water soaked margins and extends through the inner bark and cambium.

Ground squirrels burrows
Ground squirrel burrows
Identification tip: The burrow openings are about 4 inches in diameter, but can vary considerably.

Tree squirrel damage
Tree squirrel damage
Identification tip: Look for bark chewed off of scaffolds.

Crown gall
Crown gall
Identification tip: Crown gall appears as rough, abnormal galls at or below the soil surface on roots or trunk.

Fall webworm
Fall webworm tents
Identification tip: Caterpillars feed inside silken tents, enlarging the tents to cover more food as available food is consumed.


Statewide IPM Program, Agriculture and Natural Resources, University of California
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Agriculture and Natural Resources, University of California

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