California Oakworm

Populations of California oakworm (Phryganidia californica, family Dioptidae), vary from year to year with no particular pattern. Judging from calls to our office, this year’s population levels are very high. In the caterpillar stage, these insects can cause widespread damage to leaves.

The good news is healthy oaks can generally tolerate extensive loss of leaves without serious harm. UC IPM’s California Oakworm guideline provides information to help you care for your trees.

Topics include:

• Identification
• Life cycle
• Damage
• Management
• Monitoring tools
• Biological control
• Cultural controls
• Chemical controls
  

  California oakworm larva. Photo by J. Neve.