Plant Parasites of Europe

leafminers, galls and fungi

gallers on Serratula

Dichotomous table for gallers on Serratula

(inc. Klasea)

by Hans Roskam

1a Galls on stems and leaves => 2

1b Receptacle hardened, partially deformed into a bulging, tough-walled, short, conical to egg-shaped gall. One larva per chamber. S. tinctoria: Trupanea stellata and/or Urophora spoliata

1c Galls located at the base of the flower head, unilocular, ovate, thin-walled, up to 1.5 mm in length; usually the flower head is not malformed and enlarged, galls inconspicuous externally Klasea radiata, Serratula coronata: Aulacidea serratulae

1d Galls in flower heads. Klasea erucifolia, lycopifolia, nudicaulis, radiata:
Isocolus serratulae

1e Galls in flower heads, without symptoms of external deformation. Serratula spp.: Phanacis eugeniae

2a Galls in the shoot tips => 7

2b Leaves with localised or expanded malformations, which may extend into the stems => 3

3a Wart-shaped rotund or spindle-shaped swellings caused by fungi => 5

3b Expanded, glabrous or pubescent malformations caused by animal inducers => 4

4a Leaves curved at the tip, leaf blade curled, the margin ± curved downwards. Sometimes on several similarly malformed leaves terminally clustered on ± shortened internodes. S. tinctoria: Philaenus spumarius

4b More or less conspicuously stunted leaves with curved, curled or bulge-like swollen leaf blades; leaf tips often rolled. Rolls either glabrous or, like the leaf blades, with spotted, striped white or reddish erinea. S. tinctoria: Aculus rigidus

4c Conspicuous spindle-shaped galls, about 8 x 3 mm long, on petioles, also on midribs, to a lesser extent on lateral veins of the leaf blade of S. tinctorial: Loewiola serratulae

4d Lignified but relatively soft stem deformation, differently shaped, which depends on the number of larval chambers. Klasea erucifolia: Aulacidea ascanica

5a Malformations with fruiting fungal sori on the surface => 6

5b Galls hardly 1 mm long, multicellular, wart-shaped, ± golden yellow translucent; many on the underside of basal leaves. S. tinctoria: Synchytrium aureum

6a Leaf blade with rotund spindle-shaped swellings, up to 8 mm long, on the venation, usually conspicuous yellow or red margined, on the underside sometimes weakly arched, with cylindrical cup-shaped aecia occupied sori. S. coronate, tinctoria: Puccinia schroeteriana

6b Slightly bulging swellings on the midribs, less often on the lateral veins; occupied by bright brown uredinia. S. coronata, tinctorial: Puccinia hieracii

6c In SE-, C-Eu; with similar biology on Klasea bulgarica, lycopifolia, radiata; Serratula coronata, tinctoria: Puccinia schirajewski

7a Galls at the shoot tips => 8

7b Shoot terminally with spindle-shaped swelling. In the pith is a single caterpillar. S. tinctoria: Eucosma albidulana

8a Leaves on the shoot tip transformed into an erect, up to 15 mm long, cone-shaped pale gall. Several red larvae. S. tinctoria: Unidentified gall midge

8b More or less rosette- or sometimes almost bud-shaped clustering of leaves on stunted shoot tips. Infected organs often with conspicuously white or reddish pubescence. S. tinctoria: Aculus rigidus

Last modified 3.v.2020