Western Tussock Moth

Western Tussock Moth

Orgyia vetusta

Daily sighting probability <5% · Rare
at Sacramento

In 3 days ~10% in a week ~30%

20 Verified sightings at Sacramento
13 In 1 park From 2019 to 2026
April Best month
☀️ Diurnal When it's spotted

About the Western Tussock Moth

Orgyia vetusta, also known as the western tussock moth, formerly Hemerocampa vetusta, is a moth found in the Pacific States and British Columbia. The species is dimorphic; the females are flightless. The Western tussock moth is reported on virtually all California oak species as well as various fruit and nut trees, ceanothus, hawthorn, manzanita, pyracantha, toyon, walnut, and willow. There is an isolated population in Boise County, Idaho. This species has also been seen in U.S. gulf coast states such as Louisiana..

Tussock moth eggs are white and are laid in a mass, which overwinters. The female covers the eggs with setae. The caterpillars emerge in early spring (February-May) and exhibit minimal disperse via ballooning, a process by while caterpillars hang from silk threads and are spread by wind. This is also observed in other species within the family Erebidae, such as Lymantria dispar dispar. Larvae have hairs that may cause minor skin irritation or allergic reactions in humans. Adults emerge from cocoons between June and August.

Tussock moth caterpillars can cause damage to citrus orchards in Southern California.... Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Channel Islands National Park 🇺🇸 United States
~10%

More parks will be added in future updates.

Cities Where Found

# City Country Daily sighting probability
1 San Diego 🇺🇸 United States
~10%
2 San Francisco 🇺🇸 United States
~10%
3 Sacramento 🇺🇸 United States
<5%
4 Los Angeles 🇺🇸 United States
<5%

Before you go

What are the chances of seeing a Western Tussock Moth in Sacramento?

Rare

Under 5% of wildlife watchers report a Western Tussock Moth sighting in Sacramento on a given day, based on 20 verified sightings from GBIF citizen-science data. It is the 162nd most-seen of the 386 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.

When is the best time to see a Western Tussock Moth in Sacramento?

April and May

In those months about 10% of wildlife watchers report a Western Tussock Moth in Sacramento on a given day, against under 5% in June to March, the lowest months.

What time of day is best to see a Western Tussock Moth?

Between noon and 3 pm

Across all the parks we cover, that three-hour window holds the most Western Tussock Moth sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.

Is Sacramento the best place to see a Western Tussock Moth?

3rd of 4

Of the 4 cities where we can rate Western Tussock Moth sightings, Sacramento ranks 3rd at under 5%. The best odds are in San Diego (United States, about 10%) and San Francisco (United States, about 10%).

Where does the Western Tussock Moth sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Western Tussock Moth is recorded against all the insects logged in Sacramento (20 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.

← Back to Sacramento