Plantparasieten van Europa

bladmineerders, gallen en schimmels

gallers on Alchemilla

Dichotomous table for gallers on Alchemilla

by Hans Roskam

1a Leaves remarkably long stalked, more erect, their leaf blades smaller, ± pale green, with orange-yellow to -red, often crowded fungal sori on the underside => 8

1b Malformations on leaf blades or -stalks without conspicuously coloured sori => 2

2a Malformations on leaf blades caused by aphids or spittlebugs => 7

2b Other causes => 3

3a On leaf blades => 4

3b Petiole thickened. A. vulgaris: Planchonia arabidis

4a Leaf blade folded, twisted, or with minor bulge-like swellings => 5

4b Leaf blade crumpled. Infestation sites sometimes conspicuously yellowish to reddish. With single or gregarious froth-covered nymphs on underside with black margined and castellated scale surrounded by a white margin of wax. A. alpina, glabra, pratensis, vulgaris: Bactericera femoralis

5a Leaf blade folded or twisted => 6

5b Leaf blade with slightly bulge-like, ± discoloured swellings, depressions on the underside of whitish covers of sori with branched conidiophores. Alchemilla spp.: Peronospora alchemillae

6a Leaf blade irregularly folded, here and there on underside with flat, rotund depressions, not abnormally pubescent. A. vulgaris: Unidentified gall mite

6b Leaf blade variously twisted, yellowish spotted. A. fissa: Unidentified gall mite

6c Minor swellings on ± stunted leaves. A. glomerulans, murbeckiana, xanthochlora: Calepitrimerus alchemillae

7a Leaf blade acutely bent downwards over large part; crumpled and dark green close to the froth-covered nymph. Alchemilla spp.: Philaenus spumarius

7b Leaf blade strongly curled; colonies of aphids on undersides. Alchemilla spp.: Aulacorthum solani

8a Underside often completely occupied with rotund or oblong, soon coalescing, orange-yellow to red lead sporangia. Alchemilla spp.: Trachyspora alchemillae

8b Similar malformations on A. alpigena, alpina, hoppeana, indivisa, nitida, velebitica: Trachyspora melospora

8c Very close to this fungus is a species occurring with expanded mycelium on hypertrophied chlorotic shoots of A. pentaphylla, with similar biology: Trachyspora pentaphylleae

Laatste bewerking 29.iv.2020