Knopper Oak Gall Wasp - Andricus quercuscalicis

    Alternative names
    Knopper Oak Gall

    A Cynipid  gall wasp that causes a gall to form on the acorns of various oaks. The gall is seen more often than the adult wasp.

    Identification difficulty

    Adult Gall


    On Pendunculate Oak.

    When to see it

    May to July.

    Life History

    Knopper Galls develop as a chemically induced distortion of growing acorns on Pendunculate Oak trees, caused by cynipid gall wasp Andricus quercuscalicis which lays eggs within buds using the ovipositor.

    UK Status

    A recent introduction to the British Isles, first arriving in the 1960s and now found throughout England, Wales and as far north as Scotland.

    VC55 Status

    Common in Leicestershire and Rutland.

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    Leicestershire & Rutland Map

    MAP KEY:

    Yellow squares = NBN records (all known data)
    Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

    UK Map