California Oakworm
Phryganadia californica
A defoliating moth whose larvae can cause severe damage to oak trees, particularly in the San Francisco Bay area. Young larvae feed by removing leaf surfaces while older larvae completely consume leaves, potentially defoliating entire tree crowns. Repeated annual defoliation may kill trees.
Identification & Symptoms
What to Look For
Potential Damage
Lifecycle
Two complete generations annually, except southern California which may have three. Overwintering as eggs or young larvae. Larvae develop through six instars over about one month. Adults emerge May-July, with second generation emerging in late September.
Professional Treatment Approach
Imisol treatments in early spring before peak larval emergence
Target treatments to young larvae for maximum effectiveness
Imicide applications during active feeding periods
Focus on protecting live oaks which suffer more severe damage
Time treatments with first warm weather when larvae become active
Recommended Mauget Products
Imisol
Professional-grade treatment specifically effective against california oakworm.
View Product DetailsImicide
Professional-grade treatment specifically effective against california oakworm.
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