Chalastra pellurgata
In 3 days ~30% in a week ~50%
Chalastra pellurgata, also known as the brown fern moth or the pale fern looper, is a moth of the family Geometridae. This species was first described by Francis Walker in 1862. It is endemic to New Zealand and can be found throughout the country. It inhabits native forest. This species is extremely variable both in its larval and adult life stage. Larvae of this species are active during spring and summer. They feed on the fronds of fern species. C. pellurgata pupates by forming a thin cocoon on the soil amongst leaf litter and moss. Adults are on the wing throughout the year but are most common from September to March. During the day adult moths can be observed resting on dead fern fronds. They become active from dusk and are attracted to light.
This species was first described by Francis Walker in 1862 using a specimen collected in Nelson by T. R. Oxley and named Chalastra pellurgata. In 1875 Cajetan von Felder and Alois Friedrich Rogenhofer, thinking they were describing a new species, named this species Itama cinerascens. In May 1884 Edward Meyrick, thinking he was also describing a new species, named this species Stratocleis streptophora. Later in 1884 and in more... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Egmont National Park | 🇳🇿 New Zealand | |
| 2 | Rakiura National Park | 🇳🇿 New Zealand | |
| 3 | Fiordland National Park | 🇳🇿 New Zealand |
With luck
About 10% of wildlife watchers report a Chalastra pellurgata sighting in Rakiura National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 81st most-seen of the 118 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.
July
In that month about 30% of wildlife watchers report a Chalastra pellurgata in Rakiura National Park on a given day, against under 5% in January–March, May–June and August–September, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Chalastra pellurgata sightings with a recorded time, and about 8 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
2nd of 3
Of the 3 parks where we can rate Chalastra pellurgata sightings, Rakiura National Park ranks 2nd at about 10%. The best odds are in Egmont National Park (New Zealand, about 20%).
Same family: Geometridae
The closest relatives of the Chalastra pellurgata that you can see in Rakiura National Park (family Geometridae, Geometer Moths) are Forest Semilooper (about 40%), Common Forest Looper (about 30%) and Barred Pink Carpet (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Chalastra pellurgata is recorded against all the insects logged in Rakiura 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.
