Bug FAQCalifornia Oak Moth
Phryganidia californica · Order: Lepidoptera · Family: Notodontidae
Also called: California oakworm
Source: Wikipedia
Adults have a wingspan of about 30 mm and are tan to gray with noticeable wing veins. Full-grown caterpillars are also about 30 mm long, black with lengthwise yellow stripes, and feed on oak leaves, especially coast live oak. There are usually two generations per year in northern California, sometimes a third in the south, and adults are on the wing from March to November.
Source: Wikipedia
How to recognize it
Moths are tan to gray with prominent wing veins. Caterpillars are black with lengthwise yellow stripes.
Source: Wikipedia
Is it a pest in the house?
Larvae use silk threads to descend to the ground or move to another oak tree. They can feed safely during the day, protected by chemistry that deters daytime predators.
Source: Wikipedia
Where it lives
Found along the coasts of California, Oregon, and Washington. Pupae are white or yellow with black markings.
Source: Wikipedia
What it eats
Larvae feed on leaves of deciduous oaks, especially coast live oak (Quercus agrifolia).
Source: Wikipedia
Life cycle
Two generations per year in northern California, sometimes a third in southern California.
Source: Wikipedia
When you see it
Adults are active from March through November. In outbreak years, trees can be almost completely defoliated by late summer or early fall.
Source: Wikipedia
Where it comes from
Native to the coastal US states of California, Oregon, and Washington. It is the only member of its subfamily found north of Mexico.
Source: Wikipedia
Where it is found in the US
Recorded in 3 of 51 states and DC. Most records: California, Oregon, Colorado.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
How many generations does the California oak moth have each year?
Usually two generations in northern California, with a possible third generation in southern California.
Source: Wikipedia
When are adult California oak moths active?
Adults can be seen from March through November.
Source: Wikipedia
Do the larvae damage oak trees?
Yes, they feed on oak leaves and can cause heavy defoliation, especially in outbreak years.
Source: Wikipedia
Same family (Notodontidae)
White-dotted ProminentNadata gibbosaDamages trees, gardens or crops
Buff-tipPhalera bucephalaDamages trees, gardens or crops
Common Gluphisia MothGluphisia septentrionis
Pine Processionary-mothThaumetopoea pityocampaDamages trees, gardens or crops
Walnut Caterpillar MothDatana integerrimaDamages trees, gardens or crops
Unicorn ProminentCoelodasys unicornisDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Phryganidia_californica
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.