Pachycnemia hippocastanaria
In 3 days ~10% in a week ~20%
Pachycnemia hippocastanaria, the horse chestnut moth, is a moth of the family Geometridae. It is found in most of Europe. The wingspan is 28–32 mm. Adults are on wing from April to May, and again in a partial second generation in August, usually with fewer and smaller moths. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cévennes National Park | 🇫🇷 France | |
| 2 | Wadden Sea National Park | 🇩🇪 Germany | |
| 3 | Sierra de Guadarrama National Park | 🇪🇸 Spain | |
| 4 | Pyrénées National Park | 🇫🇷 France |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Porto | 🇵🇹 Portugal |
Rare
Under 5% of wildlife watchers report a Horse Chestnut Moth sighting in Pyrénées National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 1144th most-seen of the 1277 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Horse Chestnut Moth in Pyrénées National Park on a given day, so our monthly data shows no clear season.
Between 11 pm and 2 am
Across all the parks we cover, that three-hour window holds the most Horse Chestnut Moth sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
4th of 4
Of the 4 parks where we can rate Horse Chestnut Moth sightings, Pyrénées National Park ranks 4th at under 5%. The best odds are in Cévennes National Park (France, about 10%), Wadden Sea National Park (Germany, about 10%) and Sierra de Guadarrama National Park (Spain, under 5%).
Same family: Geometridae
The closest relatives of the Horse Chestnut Moth that you can see in Pyrénées National Park (family Geometridae, Geometer Moths) are Latticed Heath (about 10%), Common Heath (about 10%) and Willow Beauty (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Horse Chestnut Moth is recorded against all the insects logged in Pyrénées National Park (5 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.
