Pterallastes thoracicus
In 3 days ~10%
Pterallastes thoracicus, the goldenback fly, is an uncommon species of syrphid fly observed across central and eastern areas of the United States. Hoverflies can remain nearly motionless in flight while many are mimics of bees. The adults are also known as flower flies for they are commonly found on flowers, from which they get both energy-giving nectar and protein-rich pollen. The larvae of this species are unknown. 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 |
Rare
Under 5% of wildlife watchers report a Goldenback sighting in Washington on a given day, based on 7 verified sightings from GBIF citizen-science data. It is the 1424th most-seen of the 1807 insects we can rate there. Over three days the chance rises to about 10%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Goldenback in Washington on a given day, so our monthly data shows no clear season.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Goldenback sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Only Washington, in our data
Washington is the only city on Wallace's Line with enough records to rate Goldenback sightings: under 5% of wildlife watchers there report one on a given day.
Same family: Syrphidae
The closest relatives of the Goldenback that you can see in Washington (family Syrphidae, Hover Flies) are Eastern Calligrapher (about 10%), Margined Calligrapher (about 10%) and Transverse-Banded Flower Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Goldenback is recorded against all the insects logged in Washington (7 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.
