Brachypalpus oarus
In 3 days ~10% in a week ~30%
Brachypalpus oarus, the eastern catkin, is a common species of syrphid fly first officially described by Walker in 1849. 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 of the rat-tailed type feeding on decaying sap under tree bark. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Shenandoah National Park | 🇺🇸 United States |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Boston | 🇺🇸 United States | |
| 2 | Montreal | 🇨🇦 Canada | |
| 3 | Toronto | 🇨🇦 Canada | |
| 4 | New York City | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report an Eastern Catkin Fly sighting in Shenandoah National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 447th most-seen of the 723 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.
April
In that month about 20% of wildlife watchers report an Eastern Catkin Fly in Shenandoah National Park on a given day, against under 5% in June to February, the lowest months.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Eastern Catkin Fly sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Only Shenandoah National Park, in our data
Shenandoah National Park is the only park on Wallace's Line with enough records to rate Eastern Catkin Fly sightings: about 10% of wildlife watchers there report one on a given day.
Same family: Syrphidae
The closest relatives of the Eastern Catkin Fly that you can see in Shenandoah National Park (family Syrphidae, Hover Flies) are Eastern Calligrapher (about 20%), Common Drone Fly (about 20%) and Black-Horned Smoothtail (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Eastern Catkin Fly is recorded against all the insects logged in Shenandoah National Park (7 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.
