Selenia lunularia
In 3 days ~20% in a week ~50%
Selenia lunularia, the lunar thorn, is a moth of the family Geometridae. It is found in Europe except Iberia and Greece; also in Asia Minor, Armenia, SiberiaIssyk-Kul. The wingspan is 38–44 mm. The length of the forewings is 16–22 mm. Similar to Selenia dentaria but "Antemedian lines of forewing strongly curved, postmedian
almost straight, oblique outwards, median area very much wider posteriorly than anteriorly, wholly or in part dark-shaded.- ab. sublunaria Steph. is much darker and more purple, almost exactly the colour of some tetralunaria
- delunaria Hhn. the 2nd generation, is on an average rather smaller and with less irroration, but differs less from the 1st brood than in the other [related] species. The ground colour of the caterpillar is usually some shade of brown, ranging from greyish or greenish to reddish, variegated with darker or paler clouds, and with traces of pale lines on the back.Humps and protrusions on the fifth, eighth and ninth segments gives them the appearance of a small branch with buds and represents an excellent camouflage.
The moth flies in two generation from mid-May to mid-August [1]. The caterpillars feed on various deciduous trees, such as birch and oak. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Cévennes National Park | 🇫🇷 France | |
| 3 | Pyrénées National Park | 🇫🇷 France | |
| 4 | Bavarian Forest National Park | 🇩🇪 Germany |
With luck
About 10% of wildlife watchers report a Lunar Thorn sighting in Snowdonia National Park on a given day, based on 9 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 227th 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 50%, if each day is a fresh chance.
May
In that month about 20% of wildlife watchers report a Lunar Thorn in Snowdonia National Park on a given day, against under 5% in July to March, the lowest months.
Between 10 pm and 1 am
Across all the parks we cover, that three-hour window holds the most Lunar Thorn 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.
Yes
Of the 4 parks where we can rate Lunar Thorn sightings, Snowdonia National Park has the highest daily chance: about 10%. Next come Cévennes National Park (France, about 10%) and Pyrénées National Park (France, about 10%).
Same genus: Selenia
The closest relatives of the Lunar Thorn that you can see in Snowdonia National Park (genus Selenia) are Early Thorn (about 20%) and Purple Thorn (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Lunar Thorn is recorded against all the insects logged in Snowdonia National Park (9 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.
