Pteridium bracken
Dichotomous table for leafminers
See for the miners on bracken also Brown & McGavin (1982a) en McGavin & Brown (1986a).
1a mine in the petiole or in te lower part of the midrib => 2
1b mine in the leaf or in the tip of the midrib => 4
1c galls, etc => Tables for all parasites per species
2a mine in the top section of the midrib, causing the upper part of the leaf wither and become necrotic: Chirosia nigripes
2b mine in the lowest part of the midrib and/or the petiole => 3
3amine extending from the lower branches of the leaf down to ground level; larva: upper of two backward pointing processes of the cephalic skeleton bifid: Chirosia albitarsis
3b mine only in the lower part of the petiole; upper of two backward pointing processes simple: Chirosia crassiseta
4a mine in the midrib and blade of the leaf tip, causing the leaf to curl backwards: Chirosia grossicauda
4b mine not exclusively in the leaf tip, not causing deformation => 5
5a at the start of the mine, at the leaf underside along the midrib an elliptic egg shell; blotch, extending over several leaf segments: Chirosia cinerosa, histricina
5b no egg shell visible; corridor or secondary blotch => 6
6a frass fine-grained, locally absent; larva with chitinised head: Psychoides verhuella
6b frass in lumps and strings, nowhere absent; larva a maggot: Phytoliriomyza hilarella and pteridii