Myagrum, bird’s-eye cress

fam. Brassicaceae

1a pinnately branched gallery, main and side branches on top of the midrib and side veins: Liriomyza strigata

1b blotch, or little, not pinnately, branched gallery; mine not determined by the leaf venation => 2

1c galls, etc => 100

2a larva a maggot; mine partly or entirely upper- or lower-surface =>3

2b larva with chitinised head; mine full depth => 5

3a gallery from start to end: Chromatomyia horticola

3b blotch, may begin with a gallery => 4

4a frass powdery, in dark green “clouds” in corners of the mine, often visibly only after the mine has been opened: Scaptomyza flava

4b frass in black strings: Liriomyza xanthocera

5a larva with prolegs; older larvae live free at the underside of the leaf: Plutella xylostella

5b no prolegs; larvae mine all their life => 6

6a larva with thoracic legs: Phyllotreta nemorum

6b larva without legs: Ceutorhynchus minutus

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

104 – Diptera

104a Cecidomyiidae: Contarinia nasturtii; Gephyraulus raphanistri

105 – Hemiptera

105a Aphididae: Brevicoryne brassicae

107 – rust fungi

107a Pucciniaceae: Puccinia isiacae

109 – powdery and downy mildews

109a Erysiphaceae: Erysiphe cruciferarum

110 – other causers

110a Fungi, Albuginaceae: Albugo candida

110c Fungi, Plasmodiophoraceae: >Plasmodiophora brassicae

Not included in the key: Phytomyza rufipes.

30/07/2016