Fenusa ulmi


    The larvae of the sawfly Fenusa ulmi produce full depth blotch mines on the leaves of Elm species. The mines usually start from the angle formed by the midrib and a vein. The final mine may occupy a sizable part of the leaf. Frass in black grains, initially often in long pearl chains, in older mines in loose grains. The mines are recorded more frequently than the adults, which are rather plain, black sawflies.

    Identification difficulty

    Adult, Larva and leafmine (when the host plant is identified)


    Where Elm species are present.

    When to see it

    The mines occur from early summer once Elm is in leaf.

    UK Status

    Widespread in Britain but not well recorded.

    VC55 Status

    Uncommon or under recorded in Leicestershire and Rutland. It is believed that the Claybrooke Magna record of 2nd June 2016 is the first for our area (VC55).

    Leicestershire & Rutland Map

    MAP KEY:

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

    UK Map