Formosia speciosa
In 3 days ~20% in a week ~40%
Formosia speciosa is a species of fly in the family Tachinidae. It's also known as the Giant Black and White Fly. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Royal National Park | 🇦🇺 Australia |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Black And White Giant Fly sighting in Royal National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 147th most-seen of the 175 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
March and December–January
In those months about 10% of wildlife watchers report a Black And White Giant Fly in Royal National Park on a given day, against under 5% in February and April–November, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Black And White Giant Fly sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
Only Royal National Park, in our data
Royal National Park is the only park on Wallace's Line with enough records to rate Black And White Giant Fly sightings: about 10% of wildlife watchers there report one on a given day.
Same order: Diptera
The closest relatives of the Black And White Giant Fly that you can see in Royal National Park (order Diptera, Flies) are Pittosporum Leaf-Gall Fly (about 20%), Ommatius coeraebus (about 10%) and Garden Soldier Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Black And White Giant Fly is recorded against all the insects logged in Royal 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.
