Asian Oak Weevil

Asian Oak Weevil

Cyrtepistomus castaneus

Daily sighting probability <5% · Rare
at Washington

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

125 Verified sightings at Washington
83 In all 2 parks From 2019 to 2026
July Best month
☀️🌙 Day & Night When it's spotted

About the Asian Oak Weevil

Cyrtepistomus castaneus, the Asiatic oak weevil, is a species of Asian broad-nosed weevil in the beetle family Curculionidae. It is native to Asia, and was first found in North America in 1933. Larvae feed on root hairs in soil, whereas adult beetles are defoliators of Quercus and Acer rubrum trees. Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Great Smoky Mountains National Park 🇺🇸 United States
~10%
2 Shenandoah National Park 🇺🇸 United States
~10%

Cities Where Found

# City Country Daily sighting probability
1 Boston 🇺🇸 United States
~10%
2 Washington 🇺🇸 United States
<5%
3 New York City 🇺🇸 United States
<5%
4 Baltimore 🇺🇸 United States
<5%
5 Toronto 🇨🇦 Canada
<5%
6 Philadelphia 🇺🇸 United States
<5%
7 Chicago 🇺🇸 United States
<5%

Before you go

What are the chances of seeing an Asian Oak Weevil in Washington?

Rare

Under 5% of wildlife watchers report an Asian Oak Weevil sighting in Washington on a given day, based on 125 verified sightings from GBIF citizen-science data. It is the 240th most-seen of the 1807 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 an Asian Oak Weevil in Washington?

July to September

In those months about 10% of wildlife watchers report an Asian Oak Weevil in Washington on a given day, against under 5% in October to June, the lowest months.

What time of day is best to see an Asian Oak Weevil?

Between 9 am and noon

Across all the parks we cover, that three-hour window holds the most Asian Oak Weevil sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is seen both by day and at night.

Is Washington the best place to see an Asian Oak Weevil?

2nd of 7

Of the 7 cities where we can rate Asian Oak Weevil sightings, Washington ranks 2nd at under 5%. The best odds are in Boston (United States, about 10%).

Which relatives of the Asian Oak Weevil live in Washington?

Same family: Curculionidae

The closest relatives of the Asian Oak Weevil that you can see in Washington (family Curculionidae, True Weevils) are Yellow Poplar Weevil (about 10%) and Peach Root Weevil (about 10%), with each one's daily chance of a sighting.

Where does the Asian Oak Weevil sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Asian Oak Weevil is recorded against all the insects logged in Washington (125 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.

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