Callistephus, china aster

fam. Asteraceae

1a secundary feeding lines conspicuous; mine a broad corridor on top of the midrib, from wich fan-shaped lobes extend to the leaf margin (occurrence on this hostplant needs confirmation): Cornutrypeta spinifrons

1b secundary feeding lines not or hardly discernable; mine with different shape=> 2

1c galls, etc => 100

2a pupation within the mine => 3

2b pupation external => 5

3a mine a blotch: Calycomyza humeralis

3b a corridor => 4

4a corridor exceptionally long and narrow: Ophiomyia maura

4b corridor not unusually long and narrow: Chromatomyia syngenesiae

5a corridor pinnately branched, its main branch on top of the midrib, side branches over the lateral veins: Liriomyza strigata

5b corridor winds freely through the leaf => 6

6a larva: rear spiraculum with 3 papillae: Liriomyza bryoniae

6b rear spiraculum with 6-9 papillae: Liriomyza pusilla

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

107 – rust fungi

107a Pucciniaceae: Puccinia callistephi

109 – powdery and downy mildews

109a Erysiphaceae: Golovinomyces cichoracearum

109b Peronosporaceae: Bremia lactucae

Not included in the key: Chromatomyia syngenesiae; Liriomyza trifolii.