Diptera: Cecidomyiidae - gall midge Dasineura pteridis Photographs on Pteridum aquilinum, Bracken Host: Pteridum aquilinum Distinctly thickened downward roll on one or both sides of pinnule. Gall becoming brown or black with a single larva in each roll (white becoming pinky-orange when mature). Several generations from June onwards. Similar: Dasineura pteridicola; inconspicuous downward fold, pinnule barely thickened. One or more larvae, white when mature. Single generation, early summer. Needs rearing and expert examination to confirm

Dasineura pteridis
Lytchett Matravers, Dorset. September 2017