Pachycnemia hippocastanaria
In 3 days ~20% in a week ~30%
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 |
With luck
About 10% of wildlife watchers report a Horse Chestnut Moth sighting in Wadden Sea National Park on a given day, based on 19 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 280th most-seen of the 818 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 30%, if each day is a fresh chance.
April
In that month about 20% of wildlife watchers report a Horse Chestnut Moth in Wadden Sea National Park on a given day, against under 5% in May–June, September–October and December–March, the lowest months. That is one of Wadden Sea National Park's driest months, with about 45 mm of rain against 140 mm in November.
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.
Among the best
Of the 4 parks where we can rate Horse Chestnut Moth sightings, Wadden Sea National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Cévennes National Park (France, about 10%).
Same family: Geometridae
The closest relatives of the Horse Chestnut Moth that you can see in Wadden Sea National Park (family Geometridae, Geometer Moths) are Riband Wave (about 10%), Yellow Shell Moth (about 10%) and Small Engrailed (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 Wadden Sea National Park (19 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.
