Biscutella

fam. Brassicaceae

1a mine full depth; larva with chitinised head => 2

1b mine upper- or lower-surface (small patches may be full depth); larva a maggot => 5

1c galls, etc => 100

2a small blotch, < 1 cm; larva lives later free: Plutella xylostella

2b mine > 1 cm, may be a corridor; larva remains in the mine till pupation => 3

3a larva without feet; mine an untidy corridor: Ceutorhynchus minutus

3b larva with thoracic feet => 4

4a mine contains clear amounts of frass; final part of the mine widened into an elongate blotch: Phyllotreta nemorum

4b mine mostly without frass; corridor, not widenend in the end; alpine species: Psylliodes toelgi

5a corridor from start to end => 6

5b irregular blotch, preceded by a narrow corridor => 7

6a pinnately branched corridor, main branch overlying the midrib: Liriomyza strigata

6b corridor little branched, not associated with the midrib: Chromatomyia horticola

7a frass in thread fragments; mine in May-June: Liriomyza xanthocera

7b frass powdery, in blackish-green clouds; mine in May-October: Scaptomyza flava

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

103 – Coleoptera

103a Curculionidae: Ceutorhynchus assimilis, chalibaeus

104 – Diptera

104a Cecidomyiidae: ? Dasineura sisymbrii

107 – rust fungi

107a Pucciniaceae: Puccinia biscutellae, isiacae

109 – powdery and downy mildews

109a Peronosporaceae: Hyaloperonospora parasitica

110 – other causers

110a Fungi, Albuginaceae: Albugo candida

110b Fungi, Plasmodiophoraceae: Plasmodiophora brassicae

19/10/2016