Pteridium, bracken

fam. Dennstaedtiaceae

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 => 100

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

100a Nematoda => 101

100b Acari => 102

100c Coleoptera => 103

100e Diptera => 104

100f Hemiptera => 105

100d Hymenoptera => 106

100g rust fungi => 107

100h smut fungi => 108

100i powdery and downy mildews => 109

100j other causers => 110

102 – Acari

102a Eriophyidae: Eriophyes pteridis

104 – Diptera

104a Anthomyiidae: Chirosia crassiseta, grossicauda

104b Cecidomyiidae: Dasineura pteridicola, pteridis

106 – Hymenoptera

106a Tenthredinidae: Aneugmenus coronatus, padi, temporalis

107 – rust fungi

107a Eocronartiaceae: Herpobasidium filicinum

107b Pucciiastraceae: Uredinopsis pteridis

110 – other causers

110a Fungi, Cryptomycetaceae: Cryptomyces pteridis

110b Lepidoptera, Gelechiidae: Monochroa cytisella

See for the miners on bracken also Brown & McGavin (1982a) en McGavin & Brown (1986a).

02/10/2016