Stenoperla prasina
In 3 days ~30% in a week ~60%
Stenoperla prasina (Māori: ngarongaro wai) is a species of stonefly belonging to the family Eustheniidae. This species is endemic to New Zealand and is classified as "Not Threatened" under the New Zealand Threat Classification System. It is found on the North, South and Stewart Island / Rakiura Islands as well as on Little Barrier Island. Although adults of this species are most often coloured bright green, this species can be coloured yellow. This species inhabits clean, cold, running streams and rivers with stony bottoms within native bush. It is a known indicator of water quality. The larvae eat plant detritus and other aquatic insects while the adult insects feed on sooty mould fungi as well as other plant matter. The adults of this species are a known food source for New Zealand long tailed bats. Adults have been dissected and have been found to have been carrying Nematomorpha and trematode parasites. The New Zealand Department of Conservation classifies this species as "Not Threatened". In 2022 a specimen of this species was the 5 millionth specimen to be digitised in the Natural History Museum, London collection.
This species was described by Edward Newman in 1845... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Egmont National Park | 🇳🇿 New Zealand |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Stenoperla prasina sighting in Egmont National Park on a given day, based on 11 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 53rd most-seen of the 191 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
December
In that month about 30% of wildlife watchers report a Stenoperla prasina in Egmont National Park on a given day, against under 5% in March to September, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Stenoperla prasina sightings with a recorded time, and about 6 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
Only Egmont National Park, in our data
Egmont National Park is the only park on Wallace's Line with enough records to rate Stenoperla prasina sightings: about 10% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Stenoperla prasina is recorded against all the insects logged in Egmont National Park (11 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.
