Oncocera semirubella
In 3 days ~20% in a week ~50%
Oncocera semirubella, the rosy-striped knot-horn, is a small moth of the family Pyralidae. It is found in European regions, including the British Isles, and East Asia (e.g. China, Japan, South Korea and Taiwan). The wingspan is 26–30 mm. The forewings are light crimson or pink, sometimes much mixed with grey or dark grey, a whitish, greyish-ochreous, or grey costal streak; a broad ochreous-yellowish dorsal suffusion. Hindwings grey, slightly rosy-tinged.
The larva is bronzy-blackish, with ten indistinct greenish lines; a whitish lateral spot on 3, including a black dot; head and plate of 2 black : amongst web on Lotus. The adult moth flies in one generation by the end of June to August.[1] It is easily disturbed on short grassland, flies from dusk onwards, and is attracted to light and sugar.
The larvae feed on bird's-foot trefoil (Lotus corniculatus), white clover, Ononis species, horseshoe vetch and Medicago species. ^The flight season refers to Belgium and the Netherlands; this may vary in other parts of its range.
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| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 2 | Wadden Sea National Park | 🇩🇪 Germany | |
| 3 | Cévennes National Park | 🇫🇷 France | |
| 4 | Pyrénées National Park | 🇫🇷 France |
With luck
About 10% of wildlife watchers report a Rosy-Striped Knot-Horn sighting in Cévennes National Park on a given day, based on 26 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 283rd most-seen of the 996 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.
June to September
In those months about 10% of wildlife watchers report a Rosy-Striped Knot-Horn in Cévennes National Park on a given day, against under 5% in October to May, the lowest months. Those are among Cévennes National Park's driest months, with about 65 mm of rain a month against 260 mm in October.
Between 10 pm and 1 am
Across all the parks we cover, that three-hour window holds the most Rosy-Striped Knot-Horn 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 Rosy-Striped Knot-Horn sightings, Cévennes National Park ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Bavarian Forest National Park (Germany, about 10%) and Wadden Sea National Park (Germany, about 10%).
Same family: Pyralidae
The closest relatives of the Rosy-Striped Knot-Horn that you can see in Cévennes National Park (family Pyralidae, Pyralid Snout Moths) are Rosy Tabby (about 10%), Twin-Barred Knot-Horn (about 10%) and Long-Legged Tabby (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Rosy-Striped Knot-Horn is recorded against all the insects logged in Cévennes National Park (26 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.
