Knopper Gall Wasp

Knopper Gall Wasp

Andricus quercuscalicis

Daily sighting probability ~20% · Possible
at Liverpool

In 3 days ~50% in a week ~80%

109 Verified sightings at Liverpool
August Best month

About the Knopper Gall Wasp

Andricus quercuscalicis is a gall wasp species inducing knopper galls. Knopper galls develop as a chemically induced distortion of growing acorns on pedunculate oak (Quercus robur L.) trees, caused by gall wasps, which lay eggs in buds with their ovipositor. The gall thus produced can greatly reduce the fecundity of the oak host, making this gall potentially more of a threat to the reproductive ability of the tree than those that develop on leaves, buds, stems, etc.

The large 2 cm gall growth appears as a mass of green to yellowish-green, ridged, and at first sticky plant tissue on the bud of the oak, that breaks out as the gall between the cup and the acorn. If only a few grubs are developing within, then it may appear only as a group of bland folds. Where several grubs are competing for space the shape may become much more contorted, with several tightly bunched galls.

The word knopper derives from the German word 'Knoppe', meaning a kind of felt cap or helmet worn during the 17th century; also a small rounded protuberance, often decorative, such as a stud, a tassel or a knob. Although normally distinctive the knopper gall can, under some... Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability

More parks will be added in future updates.

Cities Where Found

# City Country Daily sighting probability
1 Liverpool 🇬🇧 United Kingdom
~20%
2 London 🇬🇧 United Kingdom
~20%
3 Manchester 🇬🇧 United Kingdom
~20%
4 Birmingham 🇬🇧 United Kingdom
~10%
5 Budapest 🇭🇺 Hungary
~10%
6 Dublin 🇮🇪 Ireland
~10%
7 Copenhagen 🇩🇰 Denmark
~10%
8 Vienna 🇦🇹 Austria
~10%
9 Leeds 🇬🇧 United Kingdom
~10%
10 Bucharest 🇷🇴 Romania
~10%

Before you go

What are the chances of seeing a Knopper Gall Wasp in Liverpool?

Possible

About 20% of wildlife watchers report a Knopper Gall Wasp sighting in Liverpool on a given day, based on 109 verified sightings from GBIF citizen-science data. It is the 93rd most-seen of the 632 insects we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.

When is the best time to see a Knopper Gall Wasp in Liverpool?

August

In that month about 40% of wildlife watchers report a Knopper Gall Wasp in Liverpool on a given day, against under 5% in March, May and November, the lowest months.

Is Liverpool the best place to see a Knopper Gall Wasp?

Yes

Of the 19 cities where we can rate Knopper Gall Wasp sightings, Liverpool has the highest daily chance: about 20%. Next come London (United Kingdom, about 20%) and Manchester (United Kingdom, about 20%).

Where does the Knopper Gall Wasp sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Knopper Gall Wasp is recorded against all the insects logged in Liverpool (109 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.

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