Plant Parasites of Europe

leafminers, galls and fungi

gallers on Malva

Dichotomous table for gallers on Malva

(incl. Lavatera, Malope)

by Hans Roskam

1a On parts above ground => 2

1b Root with nodular swellings. M. sylvestris: Meloidogyne hapla

2a Malformations on vegetative parts, only sometimes encroaching onto primordia of inflorescences => 3

2b Single mericarps between the other hardly changed mericarps conspicuously swollen, up to twice the normal size. Containing a curved beetle larva. M. alcea, multiflora, neglecta, pusilla, subovata, sylvestris, trimestris: Malvapion malvae

3a Expanded malformations of leaves caused by animals => 5

3b Localised galls on stems or small pads bearing sori on all green organs => 4

4a Leaf blades, -stalks, axial parts of shoots, even calyx and green fruits with many small, rotund or oblong, yellowish, eventually red- to dark brown spores bearing bulges. Malva spp.: Puccinia malvacearum

4b Plant ± atrophied; stem thickened, distorted; inner wall browned. M. moschata: Inducer unknown

5a Malformations with abnormal pubescence; caused by mites => 8

5b Malformations lacking abnormal pubescence; caused by aphids, scale insects or spittlebugs => 6

6a Malformations contain aphids => 7

6b Shoot axis often with several oval to spindle-shaped swellings with centrally rimmed depressions which contain a flat froth-covered nymph. M. thuringiaca: Planchonia arabidis

6c eaves curled, deflected, nest-like; often deep green at infestation site. Infestation on erect young plants usually similarly involving several leaves. Containing a froth-covered nymph. Malva spp.: Philaenus spumarius

7a Leaf margin deflected or rolled downwards. Leaf blade variously curled to undulate, sometimes arched, umbrella-like. Infestation often on terminal leaves. Aphids green. Malva spp.: Aphis umbrella

7b Similar, less conspicuous malformations caused by black aphids. M. neglecta, sylvestris: Aphis fabae

7c Leaf blade wrinkled. M. neglecta, sylvestris, thuringiaca: Aphis althaeae

7d Leaf blade ± strongly wrinkled, margins deflected. Containing pale green aphids with siphunculi half as long as to equalling cauda. M. neglecta, parviflora, pusilla, sylvestris, thuringiaca, trimestris: Acyrthosiphon malvae

8a Shoot tip stunted. Leaf blade variously disfigured and atrophied, ± thickened, rolled inwards, curled or undulate and excessively haired; often yellowing prematurely. M. alcea, moschata, thuringiaca: Aceria gymnoprocta

8b Segments of older leaves ± converging and disfigured, bag-like; usually on leaf underside on the thickened veins with dense, yellowish, felt-like pubescence. Younger leaves, densely clustered at shoot tips, similarly but more severely disfigured, often haired on both sides. Erinea also on petioles, shoot axis and calyx. M. alcea, moschata, thuringiaca: Aceria gymnoprocta

Last modified 16.v.2020