Tritoxa flexa
In 3 days ~10% in a week ~20%
Tritoxa flexa is a species of picture-winged fly in the genus Tritoxa of the family Ulidiidae. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Shenandoah National Park | 🇺🇸 United States | |
| 2 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Washington | 🇺🇸 United States | |
| 2 | Chicago | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Black Onion Fly sighting in Great Smoky Mountains National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 628th most-seen of the 822 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.
September
In that month about 10% of wildlife watchers report a Black Onion Fly in Great Smoky Mountains National Park on a given day, against under 5% in October to August, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Black Onion Fly sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is seen both by day and at night.
2nd of 2
Of the 2 parks where we can rate Black Onion Fly sightings, Great Smoky Mountains National Park ranks 2nd at under 5%. The best odds are in Shenandoah National Park (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Black Onion Fly is recorded against all the insects logged in Great Smoky Mountains National Park (5 verified sightings from 2019 to 2026), 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.
