Urophora jaceana

    Description

    The fly Urophora jaceana has a larva that produces galls on the flower heads of Common Knapweed which incorporates the receptacle and achenes. The gall is hard and woody; usually affecting most of the flower head; usually with several chambers, each with one larva.

    Identification difficulty

    Adult Gall

    Habitat

    Wherever Common Knapweed is found.

    When to see it

    Galls from August to April, or puparium May and June (in old flower head).

    UK Status

    Widespread and fairly frequent in Britain.

    VC55 Status

    Probably fairly frequent in Leicestershire and Rutland but not well recorded.

    Leicestershire & Rutland Map

    UK Map