Stigmella aceris
In 3 days ~20% in a week ~30%
Stigmella aceris is a moth of the family Nepticulidae found in Europe. It was first described by Heinrich Frey in 1857. The moth flies from May to June and again in August depending on the location and has a wingspan of 3.7–4.7 mm.
Larvae mine the leaves of its food plant making a narrow corridor usually filling the entire width of the corridor with frass. Eggs are laid on field maple (Acer campestre), Amur maple (A. ginnala), Norway maple (A. platanoides) and Tatarian maple (A. tataricum). There is some debate as to whether the moth mines the leaves of sycamore (A. pseudoplatanus) with Plant Parasites of Europe stating that it is never found on sycamore and UKmoths stating it is found on sycamore. Wikipedia →
| # | Park | Country | Daily sighting probability |
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More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Scarce Maple Pigmy sighting in Helsinki on a given day, based on 23 verified sightings from GBIF citizen-science data. It is the 280th most-seen of the 838 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.
July to October
In those months about 10% of wildlife watchers report a Scarce Maple Pigmy in Helsinki on a given day, against under 5% in November to June, the lowest months.
Among the best
Of the 10 cities where we can rate Scarce Maple Pigmy sightings, Helsinki ranks 5th at about 10%, level with the leaders once rounded. The best odds are in Budapest (Hungary, about 10%), Berlin (Germany, about 10%) and Kharkiv (Ukraine, about 10%).
GBIF citizen-science records
It is estimated from how often the Scarce Maple Pigmy is recorded against all the insects logged in Helsinki (23 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.
