Plant Parasites of Europe

leafminers, galls and fungi

gallers on Sempervivum

Dichotomous table for gallers on Sempervivum

(incl. Jovibarba)

by Hans Roskam

1a On parts above ground => 2

1b Roots with conspicuous swellings, up to 8 mm long and 5 mm broad, rotund- to oblong-oval. Sempervivum spp.: Meloidogyne hapla

2a Malformations partially excessively pubescent, usually caused by gall mites => 3

2b Several to many leaves of the rosette upright, pale green, narrowed, partially elongated, up to twice the normal size; with small, sunken, orange-red, conically protruding spermogonia and scattered aecia-like sori on upper side. Jovibarba globifera & subsp. arenaria + hirta; Sempervivum arachnoideum, calcareum, montanum, tectorum, wulfenii: Endophyllum sempervivi

3a Malformations densely pubescent => 4

3b Complete plant shortened and disfigured. Jovibarba globifera: Unidentified gall mite

3c From S. arachnoideum has been reared Aizobius sedi

4a On Jovibarba hirta. Leaves paler and densely pubescent, usually with many small, cone-shaped outgrowths, especially on upper side. Unidentified gall mite

4b On S. montanum. Rosette disfigured, ± irregular; grey-looking because of dense pubescence. Leaves sometimes with wart-like protuberances. Flowers leafy (phyllanthy). Unidentified gall mite

Last modified 31.v.2020