Ram's-horn Gall Wasp - Andricus aries

    Alternative names
    Ram's Horn Gall

    The Common name derives from the fact that the gall produced by this wasp is said to resemble the horns of a Ram in its shape. The gall is more likely to be seen than the adult wasp.

    Identification difficulty

    Adult Gall


    Anywhere that the host tree grows.

    When to see it

    April to October.

    Life History

    Not much seems to be known about the cycle of this wasp, except that it has two generations in the same year on the same host tree. Eggs are laid in the buds in April, forming the gall from May, with adults emerging in August or September. The second generation are in the gall from October, emerging in early spring.

    UK Status

    Unknown in England until its appearance in Berkshire in 1997, it is becoming more common and extending its range.

    VC55 Status

    Uncommon in Leicestershire and Rutland but seems to be increasing in numbers.

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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