Neuroterus quercusbaccarum
In 3 days ~10% in a week ~30%
The common spangle gall on the underside of leaves and the currant gall on the male catkins or occasionally the leaves, develop as chemically induced distortions on pedunculate oak (Quercus robur), or sessile oak (Quercus petraea) trees, caused by the cynipid wasp Neuroterus quercusbaccarum which has both agamic and bisexual generations.
Previous names or synonyms for this species are Neuroterus baccarum, N. lenticularis, N. malpighii, Cynips lenticularis, C. quercus-baccarum, Spathegaster baccarum, S. varius, S. interruptor. The spangle gall generation on the underside of the oak leaves are flat discs, with a distinct central elevation, slightly hairy, yellow-green at first and reddish later, attached by a short stalk. These galls are up to 6 mm in diameter, unilocular, unilarval with a whitish or yellow undersurface; they mature in September, detach and fall to the ground before the leaves themselves. The larva continue to develop in the fallen spangle and, protected by the leaf layer, they overwinter. Any spangle galls that remain attached to the leaves dry and die.
The smooth surfaced currant gall generation appears in April and lay unfertilised eggs in the staminate... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Sierra de Guadarrama National Park | 🇪🇸 Spain | |
| 3 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 4 | Cévennes National Park | 🇫🇷 France |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Liverpool | 🇬🇧 United Kingdom | |
| 2 | London | 🇬🇧 United Kingdom | |
| 3 | Birmingham | 🇬🇧 United Kingdom | |
| 4 | Manchester | 🇬🇧 United Kingdom | |
| 5 | Istanbul | 🇹🇷 Turkey | |
| 6 | Berlin | 🇩🇪 Germany | |
| 7 | Leeds | 🇬🇧 United Kingdom | |
| 8 | Paris | 🇫🇷 France | |
| 9 | Kyiv | 🇺🇦 Ukraine | |
| 10 | Bucharest | 🇷🇴 Romania |
Rare
Under 5% of wildlife watchers report a Common Spangle Gall Wasp sighting in Cévennes National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 814th most-seen of the 996 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
November
In that month about 20% of wildlife watchers report a Common Spangle Gall Wasp in Cévennes National Park on a given day, against under 5% in June–September and December–April, the lowest months. That is one of Cévennes National Park's wettest months, with about 170 mm of rain against 35 mm in July.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Common Spangle Gall Wasp sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
4th of 4
Of the 4 parks where we can rate Common Spangle Gall Wasp sightings, Cévennes National Park ranks 4th at under 5%. The best odds are in Snowdonia National Park (United Kingdom, about 10%), Sierra de Guadarrama National Park (Spain, about 10%) and Bavarian Forest National Park (Germany, about 10%).
GBIF citizen-science records
It is estimated from how often the Common Spangle Gall Wasp is recorded against all the insects logged in Cévennes National Park (6 verified sightings from 2019 to 2026), 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.
