Sinapis, mustard

fam. Brassicaceae

1a corridor, not widening into a blotch => 2

1b blotch; may be preceded by a corridor => 8

1c galls, etc. => 100

2a corridor ends upon a thick vein; from there the larva continues as a borer => 3

2b corridor not ending upon a vein => 4

3a larva a maggot: Phytomyza rufipes

3b larva with chitinised head: Ceutorhynchus pallidactylus

4a corridor pinnately branched, main branch overlying the midrib: Liriomyza strigata

4b corridor not pinnate, not associated with the midrib => 5

5a mine full depth; larva with chitinised head => 6

5b mine upper- or lower-surface; larva a maggot => 7

6a mine < 1 cm; larva, with thoracic feet, later lives free: Plutella xylostella

6b mine > 1 cm; larva, without thoracic feet, remains in the mine until close to pupation: Ceutorhynchus minutus

7a frass in discrete grains; puparium in the mine in a, usually lower-surface, pupal chamber: Chromatomyia horticola

7b frass, at least partly, in strings; pupation outside the mine: Liriomyza bryoniae

8a a blotch overlying the midrib, initially elliptic, later widening => 9

8b no association with the midrib => 10

9a frass powdery, in blackish-green clouds: Scaptomyza flava

9b frass partly in black strings: Liriomyza xanthocera

10a mine < 1 cm; larva with thoracic and abdominal feet, lives later free: Plutella xylostella

10b mine > 1 cm; larva with thoracic feet only, remains in the mine until close to pupation: Phyllotreta nemorum

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

101 – Nematoda

101a Anguinidae: Ditylenchus dipsaci

101a Heeroderidae: Heterodera cruciferae, trifolii

101c Meloidogynidae: Meloidogyne hapla

105 – Hemiptera

105a Aphididae: Brevicoryne brassicae; Lipaphis erysimi

107 – rust fungi

107a Pucciniaceae: Puccinia isiacae

109 – powdery and downy mildews

109a Erysiphaceae: Erysiphe cruciferarum

109b Peronosporaceae: Hyaloperonospora brassicae

110 – other causers

110a Fungi, Albuginaceae: Albugo candida

110b Fungi, Plasmodiophoraceae: Plasmodiophora brassicae

Not included in the key: Aulagromyza mamonowi.