Plant Parasites of Europe

leafminers, galls and fungi

gallers on Spinacia

Dichotomous table for gallers on Spinacia

by Hans Roskam

1a On leaves and stems => 2

1b Roots with slender spindle-shaped or cylindrical galls, up to about 4 mm long, bearing several side roots. S. oleracea: Meloidogyne hapla

1c Malformations known from many hosts as “leafy galls” on young spinach plants of S. oleracea, are caused by the widely distributed bacterium Rhodococcus fascians

2a Malformations caused by aphids or spittlebugs => 4

2b Malformations caused by eelworms or fungi => 3

3a Main venation as well as petioles spongy swollen; galls pale-green, ± largely encroaching into locally similarly disfigured and lacerate leaf blade. S. oleracea: Ditylenchus dipsaci

3b Developing leaves ± stunted; with yellowish-green, hunch-backed swellings and loose rolling of leaf margin. Diseased parts thickened, ± yellow-green, brittle; covered on underside with a dense, violet-grey down of branched conidiophores. S. oleracea: Peronospora farinosa

4a Malformations bearing aphids => 5

4b Malformation with conspicuous localised stunting and bending of midrib; leaf blade close to infestation deeper green; undulately lacerate and hunch-backed curled. S. oleracea: Philaenus spumarius

5a Aphids without conspicuous wax secretion => 6

5b Aphid with white-grey wax secretion. Leaf blades mainly with local, ± discoloured folds close to tip or margin, containing aphids. S. oleracea: Hayhurstia atriplicis

6a Aphid about 2.5 mm long, dull black. S. oleracea: Aphis fabae

6b Aphid 1–1.5 mm long, yellow or light- to yellow-green. S. oleracea: Aphis nasturtii

Last modified 4.v.2020