Plant Parasites of Europe

leafminers, galls and fungi

gallers on Campanula

Dichotomous table for gallers on Campanula

by Hans Roskam

1a On parts above ground => 3

1b On roots or rhizomes => 2

2a Reddish, spongy bud gall on rhizome, up to 4 mm long. Contains an orange-yellow larva. C. rotundifolia: Unidentified gall midge

b Main- and side roots with many small swellings, similar to bacterium nodules of Leguminosae. C. rapunculoides: Spongospora campanulae

3a On inflorescences, flowers or fruits => 27

3b On vegetative organs => 4

4a Malformations caused by ± early fruiting fungi at surface => 25

4b Malformations without externally developing fungal fruiting bodies => 5

5a Malformations caused by animal parasites => 6

5b Hardly 1 mm long, hemispherical, ± golden-yellow translucent wart-shaped galls, usually many on underside of rosette leaves, also on stalks as well as on basal stem parts; sometimes ± coalescing. C. herminii, patula, rotundifolia, scheuchzeri: Synchytrium aureum

6a Malformations terminally on main- and side shoots, on buds or on leaves, sometimes including stem parts => 7

6b Axial parts of stem, often the lower parts with ± expanded spindle-shaped swelling with single or several rimmed depressions containing froth-covered nymphs of causers. Campanula spp.: Planchonia arabidis

7a Malformations mainly on leaves, sometimes encroaching onto stems => 14

7b Malformations on shoot tips or on buds => 8

8a Galls loose, spindle-shaped, consisting of ± unfolded leaves, also tuft-like => 11

8b Galls closed, compact, ± onion-like, usually fleshy => 9

9a Rotund or egg-shaped galls, up to 5 mm long, on shoot tips or lateral buds; on larger organs sometimes ± joined into larger complexes => 10

9b Similar, often more slender gall, up to 8 mm long. Also flower primordia severely stunted and disfigured, sometimes overtopped by calyx lobes. Containing several red larvae. C. rapunculus: Dasineura rapunculi

10a Onion-like galls in axillary buds; often overtopped by short rudiments of leaf blades; on shoot tip often united into irregularly composed groups, up to 12 mm broad. Containing one or more brick-red larvae. C. cochleariifolia, persicifolia, rotundifolia, scheuchzeri, trachelium: Geocrypta campanulae

10b Similar, more egg-shaped gall. Contains single yellow-red larva. C. rotundifolia, scheuchzeri: Unidentified gall midge

11a Malformations tuft-like or elongate spindle-shaped => 12

11b Shoot tip stunted; leaves densely clustered, broadened at base and discoloured, terminally spreading; contains several white larvae in axils. C. trachelium: Unidentified gall midge

12a Tufts ± spindle-shaped => 13

12b Tuft terminally on shoot, up to 15 mm long, egg-shaped or globular, containing yellow larvae. C. glomerata: Dasineura campanularum

13a Tufts oblong spindle-shaped, with abnormal pubescence. Leaves rolled inwards and upwards or folded, thickened, abnormally pubescent. Containing a single orange larva. C. barbata, rapunculoides, thyrsoides: Unidentified gall midge

13b Similar gall, not additionally haired. Leaves rolled, slightly thickened and discoloured. Larva whitish, translucent. C. bononiensis, rapunculoides: Dasineura acuminata

14a Leaf blade rolled inwards, curled or swollen locally => 15

14b Leaves disfigured, almost felt-like pubescent. Stem shortened. C. cochlerariifolia, rotundifolia: cf. Aceria campanulae

15a Rolling or curls of leaf blade => 17

15b Leaf blade with ± expanded swelling => 16

16a Crater-shaped, greenish, wrinkled rimmed proliferation on upper side, close to midrib or a side vein; venation disfigured and thickened. C. bononiensis: Inducer unknown

16b Midrib and shortened stalk of several variously distorted rosette leaves swollen, spongy. Tissue brittle, pale green. Galls variously encroaching into the ± stunted leaf blade. C. barbata, carpatica, persicifolia: Ditylenchus dipsaci

17a Leaf blade with margin loosely rolled inwards and ± protruding, curls, caused by aphids or spittlebugs => 22

17b Narrow marginal roll, caused by gall mites or gall midges => 18

18a Margin rolled upwards, with cartilaginous or fleshy thickening, ± discoloured. Midge galls => 21

18b Narrow roll upwards, not discoloured. Mite galls => 19

19a On species with small leaves => 20

19b On C. latifolia, trachelium: Unidentified gall mite

20a Leaf roll tubular, narrow, sometimes remarkably thickened, not conspicuously felt-like pubescent. C. cochleariifolia, rotundifolia: Aceria campanulae

20b Similar roll with abnormal, ± felt-like pubescence. C. cochleariifolia, scheuchzeri, rotundifolia: Unidentified gall mite

21a Roll usually discoloured violet; especially on upper leaves of sterile shoots, also on leaves inserted on roots. Leaf blades sometimes bulging. Usually containing only a single red larva. C. cochleariifolia, latifolia, ? rotundifolia, scheuchzeri: Dasineura thomasi

21b Leaf blade often with cartilaginous, ± wrinkled, usually discoloured upwards roll on both sides. C. bononiensis, rapunculoides: Dasineura acuminata

22a Leaf blade rolled inwards, caused by aphids => 23

22b Leaves loosely deflected, roll- or spoon-like; curled and deep green close to infestation. Contains froth-covered nymph. Sometimes several similarly curved leaves are loosely converging, nest-like, on locally ± stunted and distorted stem. Campanula spp.: Philaenus spumarius

23a Leaves rolled downwards or bent and curled => 24

23b Leaves rolled upwards; stem with shortened, twisted internodes. C. rotundifolia: Unidentified aphid

24a Leaves rolled downwards. Aphid dark red-brown, with rows of black dots, making dark red spots if crushed. Mainly on C. rapunculoides, also on C. cervaria, glomerata, patula, sibirica, trachelium: Uroleucon rapunculoides

24b Leaves deflected, ± curled. Aphids black. C. rapunculoides, trachelium: Aphis fabae

25a Leaves thickened at infestation site, yellowish-green, with whitish-grey down of branched conidiophores on underside. Often the entire plant stunted; leaves in rosettes, non-flowering. C. rapunculoides: Peronospora sp.

25b Upper side of the leaves with pale, slightly embossed patches; on the corresponding underside is a greyish white fungal bloom, consisting of erect, distally strongly branched conidiophores. C. rapunculoides, rapunculus: Peronospora erinicola

25c Sori rust-brown, usually on leaf underside; causing facultatively minor swellings and distortions on venation, on petioles and young stem parts. Telia with 2-celled teliospores, provided with minute warts. Uredinia absent. Usually rare, biologically specialised, also morphologically distinct rusts of the species complex: Puccinia campanulae s. lat.

a On C. cochleariifolia: Puccinia rytzii

b On C. rapunculus: Puccinia campanulae

c On C. rotundifolia: Puccinia campanulae-rotundifoliae

d On C. scheuchzeri: Puccinia campanulae-scheuchzeri

e On C. uniflora: Puccinia novae-zembliae; distinguished by glabrous spore walls

f Rust fungi reported from C. glomerata, rapunculoides, trachelium, etc., are assigned to above-mentioned species complex

26a On flowers and inflorescences => 28

26b Ovaries or fruit, including receptacle, succulent, swollen, sometimes distorted; pistil and stigmas thickened, greened; the remaining flower parts necrotic. Contains a single or several larvae. Campanula spp.: Miarus campanulae

27a Flowers or inflorescence greened or leafy => 31

27b Malformation of inflorescence primordia or of flower buds, flowers lacking conspicuous greening => 28

28a Flowers, flower buds unopened and thickened => 29

28b Primordia of inflorescences severely stunted, ± reddened. Flower primordia clustered; especially ovaries disfigured and overtopped by the distorted calyx lobes. Containing several red larvae. C. rapunculus: Dasineura rapunculi

29a Flower buds inflated => 30

29b Flower buds transformed into a succulent, onion-like gall. Contains a single or several brick-red larvae. C. cochleariifolia, persicifolia, rotundifolia, scheuchzeri, trachelium: cf. Geocrypta campanulae

30a The unopened flowers are strongly enlarged at base. Calyx ± stunted; stamens thickened. Larvae white, jumping. C. barbata, cochleariifolia, rapunculoides, rhomboidalis, rotundifolia, scheuchzeri, trachelium: Contarinia campanulae

30b Similar malformations on C. cochleariifolia, rotundifolia, scheuchzeri containing white, non-jumping larvae: Dasineura campanulae

= The curculionid Miarus graminis causes galled flowers of C. glomerata, rotundifolia, trachelium.

31a Flowers greened. C. rotundifolia: Aceria chloranthes

31b Many flowers completely greened over large parts; stunted inflorescence excessively branched and, especially on side branches, the small leaves densely clustered, rolled and curled, often with proliferations on upper side. Host often pubescent with excessive development of hairs. Campanula spp.: Aculus schmardae

Last modified 30.iv.2020