Operophtera brumata
In 3 days ~20% in a week ~40%
The winter moth (Operophtera brumata) is a moth of the family Geometridae. It is an abundant species in Europe and the Near East and a famous study organism for evaluating insect population dynamics. It is one of very few lepidopterans of temperate regions in which adults are active in late autumn and early winter. The females of this species are virtually wingless and cannot fly, but the males are fully winged and fly strongly. After the initial frosts of late fall, the females emerge from their pupae, walk to and up trees and emit pheromones in the evening to attract males. After fertilization, they ascend to lay, on average, around 100 eggs each. Typically, the larger the female moth is, the more eggs she lays.
The winter moth is considered an invasive species in North America. Nova Scotia, Canada, experienced the first confirmed infestations in the 1930s. It was later accidentally introduced to Oregon in the 1950s and the Vancouver area of British Columbia around 1970. Defoliation by the moth was first noted in eastern states of the United States in the late 1990s, and is now well established in Massachusetts, Rhode Island, New Hampshire and Maine. The winter moth is confirmed present in British Columbia, Washington and Oregon. In Massachusetts, the moths have attracted the attention of several media outlets due to the severity of the infestation. Efforts at biological control are underway. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 2 | Cévennes National Park | 🇫🇷 France | |
| 3 | Pyrénées National Park | 🇫🇷 France | |
| 4 | Wadden Sea National Park | 🇩🇪 Germany |
With luck
About 10% of wildlife watchers report a Winter Moth sighting in Rotterdam [The Hague] on a given day, based on 64 verified sightings from GBIF citizen-science data. It is the 107th most-seen of the 355 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.
December
In that month about 40% of wildlife watchers report a Winter Moth in Rotterdam [The Hague] on a given day, against under 5% in January to October, the lowest months.
Between 4 and 7 pm
Across all the parks we cover, that three-hour window holds the most Winter Moth sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is seen both by day and at night.
Among the best
Of the 25 cities where we can rate Winter Moth sightings, Rotterdam [The Hague] ranks 9th at about 10%, level with the leaders once rounded. The best odds are in Prague (Czechia, about 10%), Lyon (France, about 10%) and Vienna (Austria, about 10%).
Same family: Geometridae
The closest relatives of the Winter Moth that you can see in Rotterdam [The Hague] (family Geometridae, Geometer Moths) are Small Dusty Wave (about 10%), Single-Dotted Wave (about 10%) and Yellow Shell Moth (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Winter Moth is recorded against all the insects logged in Rotterdam [The Hague] (64 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.
