Plant Parasites of Europe

leafminers, galls and fungi

gallers on Convolvulus

Dichotomous table for gallers on Convolvulus

(incl. Calystegia)

by Hans Roskam

1a On parts above ground => 2

1b Roots with small nodular to spindle-shaped swellings. Convolvulus sp.:
Meloidogyne hapla

2a On shoots and leaves => 3

2b vary, and also capsules, in usually conspicuously smaller flowers hardly changed; sometimes remarkably narrowed in apical part; anthers almost always sessile, swollen, at first like the nectar ring temporarily bearing whitish to yellowish sori containing conidia. Spores in balls, pale brown-red; mainly in several or all, at first slightly swollen, later on aborted seed primordia. Convolvulus arvensis, Calystegia sepium, soldanella: Thecaphora seminis-convolvuli

3a Malformations caused by aphids, psyllids or spittlebugs => 7

3b Malformations caused by different inducers => 4

4a Galls caused by parasitic animals => 5

4b Usually aecia arranged in a circle on the underside of undisfigured leaves. Sori on veins, stalks and axial shoot parts sometimes slightly swollen. Convolvulus spp.; Calystegia spp.: Puccinia convolvuli

4c Stems with a white cover, at first shiny, later powdery. Parts of the plant may become disfigured. C. pentapetaloides, siculus, tricolor: Albugo convolvulacearum

5a Malformation of many terminal leaves => 6

5b Shoots or petioles with ± expanded swellings on all- or one-side, pale green, spongy, on surface ± wrinkled. Leaves ± distorted. Convolvulus arvensis: Ditylenchus dipsaci

6a Terminal shoots or plant completely and severely stunted, axial parts shortened; leaf blades folded upwards, variously curved and rolled loosely, swollen, yellowish or crimson discoloured, abnormally, ± densely pubescent. Convolvulus althaeoides, arvensis, cantabrica, thunbergii: Aceria convolvuli

6b Similar, but glabrous malformations usually without distinct stunting of shoots, on loosely arranged, ± erectly folded and sickle-shaped disfigured leaves. Convolvulus arvensis: Aculus convolvuli and or Aceria malherbae, the latter also on Calystegia sepium

7a Malformations of often numerous leaves on shoots. Caused by aphids => 8

7b Leaves on the distinctly shortened terminal internodes clustered and stunted, with several converging ± nest-like; leaf blades partially distorted and deep green. Contain a froth-covered nymph. Convolvulus arvensis, Calystegia sepium: Philaenus spumarius

7c Pustule, 2 mm across, protruding on both sides of leaf blade, with exit hole on leaf underside, surrounded by white hairs. Convolvulus canariensis: Unidentified psyllid

8a Leaves folded, partially rolled, ± curled; contain black aphid. Convolvulus arvensis, Calystegia sepium: Aphis fabae

8b Leaves curled, curved downwards. Aphid green. Convolvulus arvensis, Calystegia sepium: Myzus persicae

Last modified 1.v.2020