Idaea inversata
In 3 days ~20% in a week ~40%
Idaea inversata, the purple wave, is a moth of the family Geometridae. The species was first described by Achille Guenée in 1857. It is found along the east coast of Australia. Idaea inversata is externally very similar to I. costaria but lacks the two-coloured head pattern of that species. I. costaria has a creamy-white patch between the antennae, whereas I. inversata is dark reddish throughout this area. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Lamington National Park | 🇦🇺 Australia | |
| 2 | Blue Mountains National Park | 🇦🇺 Australia | |
| 3 | Great Otway National Park | 🇦🇺 Australia |
With luck
About 10% of wildlife watchers report a Purple Wave sighting in Blue Mountains National Park on a given day, based on 23 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 174th most-seen of the 789 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.
February–April and September–December
In those months about 10% of wildlife watchers report a Purple Wave in Blue Mountains National Park on a given day, against under 5% in January and May–August, the lowest months.
Between 7 and 10 pm
Across all the parks we cover, that three-hour window holds the most Purple Wave sightings with a recorded time, and about 6 in 10 of them come between 6 pm and 6 am: it is most active around dawn and dusk.
Among the best
Of the 3 parks where we can rate Purple Wave sightings, Blue Mountains National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Lamington National Park (Australia, about 10%).
Same genus: Idaea
The closest relatives of the Purple Wave that you can see in Blue Mountains National Park (genus Idaea) are Idaea halmaea (about 10%) and Flecked Wave Moth (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Purple Wave is recorded against all the insects logged in Blue Mountains National Park (23 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.
