Caloptilia alchimiella
In 3 days ~10% in a week ~30%
Caloptilia alchimiella (commonly known as yellow-triangle slender) is a moth of the family Gracillariidae. It is found in Europe and the Near East. The wingspan is 10–13 millimetres (0.39–0.51 in). Forewings purplish - ferruginous; dorsum suffused with yellow towards base; a large triangular yellow median costal blotch, apex often rounded. Hindwings dark grey..
The moth flies from May to July depending on the location. The larvae feed on Quercus species, Castanea sativa and Fagus sylvatica. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Bavarian Forest National Park | 🇩🇪 Germany |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Yellow-Triangle Slender sighting in Bavarian Forest National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 727th most-seen of the 1115 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
May and July–August
In those months about 10% of wildlife watchers report a Yellow-Triangle Slender in Bavarian Forest National Park on a given day, against under 5% in June and September–April, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Yellow-Triangle Slender sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Only Bavarian Forest National Park, in our data
Bavarian Forest National Park is the only park on Wallace's Line with enough records to rate Yellow-Triangle Slender sightings: about 10% of wildlife watchers there report one on a given day.
Same family: Gracillariidae
The closest relatives of the Yellow-Triangle Slender that you can see in Bavarian Forest National Park (family Gracillariidae, Leaf Blotch Miner Moths) are Horse-Chestnut Leafminer (about 10%), Locust Digitate Leafminer Moth (about 10%) and Lime Leafminer (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Yellow-Triangle Slender is recorded against all the insects logged in Bavarian Forest 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.
