Tortrix viridana
In 3 days ~10% in a week ~20%
The green oak tortrix, Tortrix viridana, also known as the European oak leafroller and the green oak moth, is a distinctive green moth whose larvae feed on tree leaves, especially oak. The head, forebody and front wings are green, the hind wings lightly greyish. The wingspan is 18-24 millimetres.
An infestation of the larvae can defoliate an oak tree. The adult female lays its eggs next to leaf buds, which the larvae consume when they emerge. As the larvae grow bigger they eat larger leaves, and then roll themselves up in a full-sized leaf to pupate.
Larvae occur from April to June; adults are on wing in June and July. The Ichneumon wasp Dirophanes invisor is a parasitoid which specializes on T. viridana. They are commonly found in many parts of Britain. In the Butterfly Conservation’s Microlepidoptera Report 2011 this species was classified as common. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cévennes National Park | 🇫🇷 France | |
| 2 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 3 | Wadden Sea National Park | 🇩🇪 Germany | |
| 4 | Sierra de Guadarrama National Park | 🇪🇸 Spain |
Rare
Under 5% of wildlife watchers report a Green Oak Tortrix sighting in Vienna on a given day, based on 13 verified sightings from GBIF citizen-science data. It is the 895th most-seen of the 1406 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.
June
In that month about 10% of wildlife watchers report a Green Oak Tortrix in Vienna on a given day, against under 5% in July to May, the lowest months. That is one of Vienna's wettest months, with about 90 mm of rain against 40 mm in February.
Between 6 and 9 am
Across all the parks we cover, that three-hour window holds the most Green Oak Tortrix sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
19th of 19
Of the 19 cities where we can rate Green Oak Tortrix sightings, Vienna ranks 19th at under 5%. The best odds are in London (United Kingdom, about 10%), Sofia (Bulgaria, about 10%) and Liverpool (United Kingdom, about 10%).
GBIF citizen-science records
It is estimated from how often the Green Oak Tortrix is recorded against all the insects logged in Vienna (13 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.
