The larva mines the leave of Geranium and Erodium species. The start of the mine is corridor-like and usually follows the leaf margin, before widening considerably into a secondary blotch, with irregular sides. Primary and secondary feeding lines are clearly visible and frass is mostly in large clumps.

See the National Agromyzidae Recording Scheme website for further details of larva and adult insect.

ref.: Warrington, B.P. (2023).  Agromyza nigrescens. Accessed at https://agromyzidae.co.uk/species/agromyzidae/agromyzinae/agromyza/agromyza-nigrescens/ on 13/12/2023)

Leaf-mine Adult

Leafmine: Please provide photographs including a back-lit image showing the frass pattern.  Please also state the host plant.

Click on the 'further details' link in the 'Description' section above.  Then click on the Phenology tab which will provide phenology details for both adult and larval stages.

Nationally Scarce B.

Warrington, B. P. 2022. A provisional review of the status of Agromyzidae in Great Britain & Northern Ireland

Rarely recorded in Leicestershire and Rutland.