Andricus aries
In 3 days ~10% in a week ~20%
Andricus aries is a species of gall-forming wasps, in the genus Andricus. The species was named by the French entomologist Joseph-Étienne Giraud, in 1859. It is commonly found in eastern Europe and during the 21st century has spread to western Europe.
Adults lay their eggs on various species of oak, including Quercus robur, Q. petraea, Q. pubescens and Q. cerris, The developing larvae cause the trees to create an elongated gall, reminiscent of a ram's horn, hence the epithet aries and the vernacular name "ram's horn gall wasp". Green at first, the gall can be reduced to a single strap or can just be 5 mm long. It later hardens, turns brown and is especially variable when the gall contains inquilines (Synergus species). A. aries does not cause galls to form on acorns but causes galls to develop on leaf buds on twigs, these have a variety of forms which are due to the activities of parasites and inquilines. Its sexual stage is found on the catkins of Evergreen Oak In northwestern Europe, at least, their reproduction is solely asexual generation, however, experiments have demonstrated that newly emerged females will lay eggs in the axillary buds of Quercus cerris. A... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | London | 🇬🇧 United Kingdom | |
| 2 | Liverpool | 🇬🇧 United Kingdom | |
| 3 | Birmingham | 🇬🇧 United Kingdom | |
| 4 | Vienna | 🇦🇹 Austria |
Rare
Under 5% of wildlife watchers report a Ram's Horn Gall Wasp sighting in Vienna on a given day, based on 21 verified sightings from GBIF citizen-science data. It is the 666th 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.
December to February
In those months about 10% of wildlife watchers report a Ram's Horn Gall Wasp in Vienna on a given day, against under 5% in March to November, the lowest months.
4th of 4
Of the 4 cities where we can rate Ram's Horn Gall Wasp sightings, Vienna ranks 4th at under 5%. The best odds are in London (United Kingdom, about 10%), Liverpool (United Kingdom, about 10%) and Birmingham (United Kingdom, about 10%).
Same genus: Andricus
The closest relatives of the Ram's Horn Gall Wasp that you can see in Vienna (genus Andricus) are Knopper Gall Wasp (about 10%), Andricus dentimitratus (about 10%) and Andricus caputmedusae (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Ram's Horn Gall Wasp is recorded against all the insects logged in Vienna (21 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.
