Cameraria ohridella
In 3 days ~20% in a week ~40%
The horse-chestnut leaf miner (Cameraria ohridella) is a leaf-mining moth of the family Gracillariidae. The horse-chestnut leaf miner was first observed in North Macedonia in 1984, and was described as a new species in 1986. Its larvae are leaf miners on the common horse-chestnut (Aesculus hippocastanum). The horse-chestnut leafminer was first collected and inadvertently pressed in herbarium sheets by the botanist Theodor von Heldreich in central Greece in 1879.
Cameraria ohridella causes significant damage, mainly late summer browning, to the appearance of horse-chestnut trees. Despite the poor appearance of these infested trees, there is no evidence that damage by the moth leads to tree death. Seed weight, photosynthetic storage and reproductive capacity may however be reduced. Trees survive repeated infestations and re-flush normally in the following year. It appears that most of the damage caused by the moth occurs too late in the growing season to greatly affect tree performance. Consequently, there is no reason to fell and remove trees just because they are attacked by C. ohridella.
The larva feeds in a mine in the leaves of the tree, damaging the leaves and stunting... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Triglav National Park | 🇸🇮 Slovenia | |
| 2 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 3 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 4 | Wadden Sea National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Liverpool | 🇬🇧 United Kingdom | |
| 2 | Kyiv | 🇺🇦 Ukraine | |
| 3 | Kharkiv | 🇺🇦 Ukraine | |
| 4 | London | 🇬🇧 United Kingdom | |
| 5 | Minsk | 🇧🇾 Belarus | |
| 6 | Sofia | 🇧🇬 Bulgaria | |
| 7 | Berlin | 🇩🇪 Germany | |
| 8 | Manchester | 🇬🇧 United Kingdom | |
| 9 | Warsaw | 🇵🇱 Poland | |
| 10 | Birmingham | 🇬🇧 United Kingdom |
With luck
About 10% of wildlife watchers report a Horse-Chestnut Leafminer sighting in Helsinki on a given day, based on 30 verified sightings from GBIF citizen-science data. It is the 202nd 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 40%, if each day is a fresh chance.
June to October
In those months about 10% of wildlife watchers report a Horse-Chestnut Leafminer in Helsinki on a given day, against under 5% in November to May, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Horse-Chestnut Leafminer sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
20th of 33
Of the 33 cities where we can rate Horse-Chestnut Leafminer sightings, Helsinki ranks 20th at about 10%. The best odds are in Liverpool (United Kingdom, about 30%), Kyiv (Ukraine, about 30%) and Kharkiv (Ukraine, about 20%).
GBIF citizen-science records
It is estimated from how often the Horse-Chestnut Leafminer is recorded against all the insects logged in Helsinki (30 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.
