Neuroterus numismalis
In 3 days ~20% in a week ~40%
Neuroterus numismalis is a gall wasp that forms chemically induced leaf galls on oak trees. It has both bisexual and agamic (parthenogenetic) generations and forms two distinct galls on oak leaves, the silk button gall and blister gall. The galls can be very numerous with more than a thousand per leaf.
Neuroterus reaumuri, N. vesicator, Spathegaster vesicatrix, Cynips numismalis, and C. quercus-tiarae are previous binomials found in the literature. This silk button spangle gall has a cover of golden hairs that give the impression of silk thread. The 0.3 cm button-shaped galls have a pronounced concavity and sit tightly against the leaf lamina.
Blister galls are about 0.3 cm in diameter and green or greyish in colour; well camouflaged with the leaf lamina. The gall has narrow ridges running downwards on all sides from a central papilla on the upper surface and sometimes on the lower surface as well. Both galls are both unilocular and unilarval.
The female wasp of the bisexual generation is about 1.8–2.4 mm in length; largely brown in colour with clear wings and hairy legs. The male is also winged and slightly shorter... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Liverpool | 🇬🇧 United Kingdom | |
| 2 | London | 🇬🇧 United Kingdom | |
| 3 | Birmingham | 🇬🇧 United Kingdom | |
| 4 | Manchester | 🇬🇧 United Kingdom | |
| 5 | Leeds | 🇬🇧 United Kingdom | |
| 6 | Warsaw | 🇵🇱 Poland | |
| 7 | Berlin | 🇩🇪 Germany | |
| 8 | Essen | 🇩🇪 Germany | |
| 9 | Hamburg | 🇩🇪 Germany | |
| 10 | Milan | 🇮🇹 Italy |
With luck
About 10% of wildlife watchers report a Silk-Button Spangle Gall Wasp sighting in Snowdonia National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 294th most-seen of the 387 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.
September
In that month about 20% of wildlife watchers report a Silk-Button Spangle Gall Wasp in Snowdonia National Park on a given day, against under 5% in November to June, the lowest months.
Between 3 and 6 pm
Across all the parks we cover, that three-hour window holds the most Silk-Button Spangle Gall Wasp sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Only Snowdonia National Park, in our data
Snowdonia National Park is the only park on Wallace's Line with enough records to rate Silk-Button Spangle Gall Wasp sightings: about 10% of wildlife watchers there report one on a given day.
Same genus: Neuroterus
The closest relatives of the Silk-Button Spangle Gall Wasp that you can see in Snowdonia National Park (genus Neuroterus) are Common Spangle Gall Wasp (about 10%) and Oyster Gall Wasp (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Silk-Button Spangle Gall Wasp is recorded against all the insects logged in Snowdonia 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.
