Bug FAQRosy-striped Knot-horn
Oncocera semirubella · Order: Lepidoptera · Family: Pyralidae
The rosy-striped knot-horn has a wingspan of about 26 to 30 mm and pinkish forewings with grey and yellowish markings. Adults fly from late June through August, are attracted to light and sugar, and are most often seen in short grassland.
Source: Wikipedia
How to recognize it
Forewings are light crimson or pink, often mixed with grey, and show a whitish-grey costal streak and a broad yellow-ochre dorsal area; hindwings are grey with a slight rosy tint.
Source: Wikipedia
Size
The moth’s wingspan ranges from 26 to 30 mm.
Source: Wikipedia
Where it lives
It is easily disturbed in short grassland.
Source: Wikipedia
What it eats
Larvae feed on bird’s-foot trefoil, white clover, Ononis species, horseshoe vetch and various Medicago species.
Source: Wikipedia
Life cycle
Adults emerge in a single generation that flies from late June to August.
Source: Wikipedia
When you see it
The moth is active from the end of June through August, flying after dusk and being drawn to light and sugary substances.
Source: Wikipedia
Where it comes from
It occurs across Europe, including the British Isles, and in East Asian countries such as China, Japan, South Korea and Taiwan.
Source: Wikipedia
More photos
Questions people ask
When are rosy-striped knot-horn moths active?
They fly from late June to August, mainly after dusk and are attracted to light and sugar.
Source: Wikipedia
What do the larvae eat?
The caterpillars feed on bird’s-foot trefoil, white clover, Ononis, horseshoe vetch and Medicago plants.
Source: Wikipedia
Same family (Pyralidae)
Indian-Meal MothPlodia interpunctellaCan damage your home
Greater Wax MothGalleria mellonella
Mediterranean Flour MothEphestia kuehniellaCan damage your home
Meal mothPyralis farinalisDamages trees, gardens or crops
Bee MothAphomia sociellaNuisance, not dangerous
Yellow-fringed Dolichomia MothHypsopygia olinalisSources
- Wikipedia: https://en.wikipedia.org/wiki/Oncocera_semirubella
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.