Verbascum, mullein

1a mine upper- or lower-surface; larva a maggot => 2

1b mine full depth; larva with chitinised head => 5

1c fleck mine: Apterona helicoidella

1d galls, etc => 100

2a large, pale, upper-surface blotch: Amauromyza verbasci

2b corridor mine => 3

3a corridor pinnately branched, main branch overlying the midrib: Liriomyza strigata

3b corridor not pinnate, independent of the midrib => 4

4a puparium in the mine; frass in isolated grains: Chromatomyia horticola

4b pupation outside the mine; frass in thread fragments: Liriomyza bryoniae

5a mine begins in the leaf base or in the midrib; larva without feet: Orthochaetes insignis

5b mine begins at a random position; larva with thoracic feet: Apteropeda orbiculata

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: Rhinusa asellus, neta, tetra

105 – Hemiptera

105a Aphididae: Aphis verbasci, wellensteini

107 – rust fungi

107a Pucciniaceae: Uromyces verbasci

109 – powdery and downy mildews

109a Erysiphaceae: Golovinomyces verbasci; Leveillula verbasci

109b Peronosporaceae: Peronospora verbasci

110 – oher causers

110a Bacteria, Actinomycetales: Rhodococcus fascians

110b Fungi, Capnodiales: Ramularia variabilis

Not included in the key: Coleophora pennella; Nothris verbascella; Ophiomyia verbasci.