Apotomis betuletana
In 3 days ~10% in a week ~20%
Apotomis betuletana is a moth of the family Tortricidae. It is found in most of Europe. It is also found in the eastern part of the Palearctic realm. The wingspan is 16–20 mm. The forewings are white, sometimes partly ochreous - tinged, with some grey striae posteriorly. The basal patch and central fascia are dark brown, black -marked, the included space dark ashy-fuscous, all slightly whitish sprinkled, on fold sometimes more mixed with white. The posterior edge of fascia is nearly straight, followed in middle by a faint pinkish-ochreous tinge. Hindwings grey, darker posteriorly. The larva is green, incisions yellowish; dorsal and subdorsal lines grey-green; tubercular spots yellow; head yellow-green; plate of 2 pale green. Julius von Kennel provides a full description.
Adults are on wing from July to September. The larvae feed on Betula species. They spin and roll the leaves of their host plant. The larvae can be found from May to June. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Wadden Sea National Park | 🇩🇪 Germany | |
| 2 | Bavarian Forest National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Helsinki | 🇫🇮 Finland |
Rare
Under 5% of wildlife watchers report a Birch Marble sighting in Helsinki on a given day, based on 9 verified sightings from GBIF citizen-science data. It is the 553rd most-seen of the 838 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.
July and August
In those months about 10% of wildlife watchers report a Birch Marble in Helsinki on a given day, against under 5% in September to June, the lowest months.
Between 10 pm and 1 am
Across all the parks we cover, that three-hour window holds the most Birch Marble sightings with a recorded time, and about 8 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Only Helsinki, in our data
Helsinki is the only city on Wallace's Line with enough records to rate Birch Marble sightings: under 5% of wildlife watchers there report one on a given day.
Same family: Tortricidae
The closest relatives of the Birch Marble that you can see in Helsinki (family Tortricidae, Tortricid Leafroller Moths) are Barred Marble (about 10%), Common Marble (about 10%) and White-Foot Bell (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Birch Marble is recorded against all the insects logged in Helsinki (9 verified sightings), 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.
