Polygonum, small-leaved knotgrass

The classical genus Polygonum has been split into Fallopia (incl. Reynoutria), Persicaria (incl. Bistorta), and Polygonum.

1a mine small; irregular corridor or blotch, usually with a round hole at either end; older larve live free, causing window feeding: Hypera rumicis

1b eventually a large blotch, without holes; larva remains in the mine till shortly before pupation: Mantura rustica

1c gallen etc => 100

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

101b Meloidogynidae: Meloidogyne hapla

104 – Diptera

104a Cecidomyiidae: Wachtliella persicariae

107 – rust fungi

107a Pucciniaceae: Uromyces polygoni-avicularis

108 – smut fungi

108a Entylomataceae: Entyloma polygoni-amphibii

108b Microbotryaceae: Microbotryum aviculare

108c Ustilaginaceae: Melanopsichium austro-americanum, pennsylvanicum

109 – powdery and downy mildews

109a Erysiphaceae: Erysiphe polygoni; Leveillula taurica

109b Peronosporaceae: Peronospora polygoni

110 – other causers

110a Lepidoptera, Coleophoridae: Augasma aeratella

Not included in the key: Apterona helicoidella; Chrysoesthia drurella; Cnephasia lineata; Liriomyza trifolii.