Besma quercivoraria
In 3 days ~10% in a week ~20%
Besma quercivoraria, the oak besma, is a moth of the family Geometridae. The species was first described by Achille Guenée in 1857. It is found across southern Canada (from Newfoundland to British Columbia) and all of the United States except California.
Adults are sexually dimorphic. The wingspan is 27–41 mm. Adults are on wing from April to September in the south, from May to August in Ontario and from late May to July in Alberta. There are two generations per year. The larvae feed on the leaves of oak, elm, poplar, willow, Picea glauca, and mostly Betula papyrifera in southern Canada. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Great Smoky Mountains National Park | 🇺🇸 United States |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Washington | 🇺🇸 United States | |
| 2 | Boston | 🇺🇸 United States | |
| 3 | New York City | 🇺🇸 United States | |
| 4 | Chicago | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report an Oak Besma Moth sighting in Washington on a given day, based on 22 verified sightings from GBIF citizen-science data. It is the 764th 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 20%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report an Oak Besma Moth in Washington on a given day, so our monthly data shows no clear season.
Between midnight and 3 am
Across all the parks we cover, that three-hour window holds the most Oak Besma Moth sightings with a recorded time, and about half of them come between 6 am and 6 pm: it is seen both by day and at night.
Yes
Of the 4 cities where we can rate Oak Besma Moth sightings, Washington has the highest daily chance: under 5%. Next come Boston (United States, under 5%) and New York City (United States, under 5%).
Same family: Geometridae
The closest relatives of the Oak Besma Moth that you can see in Washington (family Geometridae, Geometer Moths) are Tulip-Tree Beauty (about 10%), Common Tan Wave (about 10%) and Large Lace-Border Moth (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Oak Besma Moth is recorded against all the insects logged in Washington (22 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.
