Andricus aries
In 3 days ~30% in a week ~50%
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 |
With luck
About 10% of wildlife watchers report a Ram's Horn Gall Wasp sighting in London on a given day, based on 189 verified sightings from GBIF citizen-science data. It is the 194th most-seen of the 1504 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
September and November
In those months about 20% of wildlife watchers report a Ram's Horn Gall Wasp in London on a given day, against under 5% in December, the lowest month.
Yes
Of the 4 cities where we can rate Ram's Horn Gall Wasp sightings, London has the highest daily chance: about 10%. Next come 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 London (genus Andricus) are Knopper Gall Wasp (about 20%), Oak Marble Gall Wasp (about 20%) and Oak Artichoke Gall Wasp (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 London (189 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.
