Spilomyia fusca
In 3 days ~30% in a week ~50%
Spilomyia fusca, the Bald-faced Hornet Fly, is a fairly common species of syrphid fly first officially described by Loew, 1864 This species is found in eastern North America. Hoverflies get their names from the ability to remain nearly motionless while in flight. The adults are also known as flower flies for they are commonly found around and on flowers from which they get both energy-giving nectar and protein-rich pollen. The larvae are known as the short-tailed larva tailored for moist areas such as rot holes of trees. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Acadia National Park | 🇺🇸 United States | |
| 2 | Shenandoah National Park | 🇺🇸 United States | |
| 3 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Toronto | 🇨🇦 Canada |
With luck
About 10% of wildlife watchers report a Bald-Faced Hornet Fly sighting in Acadia National Park on a given day, based on 32 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 96th most-seen of the 405 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
August
In that month about 20% of wildlife watchers report a Bald-Faced Hornet Fly in Acadia National Park on a given day, against under 5% in October to June, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Bald-Faced Hornet Fly sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 3 parks where we can rate Bald-Faced Hornet Fly sightings, Acadia National Park has the highest daily chance: about 10%. Next come Shenandoah National Park (United States, about 10%) and Great Smoky Mountains National Park (United States, under 5%).
Same genus: Spilomyia
The closest relatives of the Bald-Faced Hornet Fly that you can see in Acadia National Park (genus Spilomyia, Hornet Flies) are Four-Lined Hornet Fly (about 10%) and Eastern Hornet Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Bald-Faced Hornet Fly is recorded against all the insects logged in Acadia National Park (32 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.
