Achlya flavicornis
In 3 days ~20% in a week ~40%
Achlya flavicornis, the yellow horned, is a moth of the family Drepanidae. The species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. It is found from Europe to the eastern Palearctic ecozone.
The wingspan is 35–40 mm. The length of the forewings is 17–20 mm. The ground colour is greenish grey, sometimes speckled or dusted with darker grey. The reniform and orbicular marks are generally clear and distinct, but in some examples they are united and form a whitish blotch outlined in blackish; the cross lines are usually well defined, but in the dark grey dusted form are very obscure. The moth flies from February to April depending on the location.
The final instar larva is either off white all over or off white below the spiracles and darker greyish or olive green dorsally. There is a row of black spots and finely black-edged white dots. The insect overwinters as a pupa in a cocoon, amongst leaf litter.
The larvae feed on birch. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Yellow Horned sighting in Snowdonia National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 336th most-seen of the 387 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
In that month about 40% of wildlife watchers report a Yellow Horned in Snowdonia National Park on a given day, against under 5% in April to February, the lowest months.
Between 6 and 9 am
Across all the parks we cover, that three-hour window holds the most Yellow Horned sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Only Snowdonia National Park, in our data
Snowdonia National Park is the only park on Wallace's Line with enough records to rate Yellow Horned sightings: about 10% of wildlife watchers there report one on a given day.
Same family: Drepanidae
The closest relatives of the Yellow Horned that you can see in Snowdonia National Park (family Drepanidae, Hooktip and False Owlet Moths) are Peach Blossom Moth (about 20%), Buff Arches (about 10%) and Pebble Hook-Tip (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Yellow Horned is recorded against all the insects logged in Snowdonia National Park (6 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.
