Plant Parasites of Europe

leafminers, galls and fungi

gallers on Lithospermum

Dichotomous table for gallers on Lithospermum

(incl. Aegonychon, Buglossoides)

by Hans Roskam

1a Malformations on terminal shoot parts => 4

1b Localised galls on leaves of shoot axis => 2

2a Locally defined galls mainly on leaves, occasionally on shoot axis => 3

2b Stem with ± pronounced swellings, with froth-covered nymph in rimmed depressions. Aegonychon purpurocaeruleum, Lithospermum officinale: Planchonia arabidis

3a Less than 1 mm long, at first yellow-red, later on brownish warts, often joined into crusts; mainly on leaves, sometimes on calyx. Buglossoides arvensis: Synchytrium myosotidis

3b Much larger, on leaf blade rotund or oval, on axial parts spindle-shaped elongated, yellowish pads bearing aecia. Aegonychon purpurocaeruleum, Buglossoides arvensis, Lithospermum officinale: Aecidium lithospermi

4a Malformations, not restricted to shoot tips => 5

4b At base spoon-like broadened, thickened and abnormally haired leaves are bud- to rosette-like, clustered on the tips of main- and lateral shoots. Aegonychon purpurocaeruleum, Buglossoides arvensis, Lithospermum officinale: Dasineura lithospermi

5a Malformations caused by animals => 6

5b Fungal causers. Completely diseased leaves narrowed, pale, slightly hypertrophied and rolled downwards at margin. Covered with down of branched conidiophores on underside. Often many leaves are diseased at ends of shoots. Buglossoides arvensis, Lithospermum officinale: Peronospora lithospermi

6a Similar malformations, associated with curling and twisting of leaf blades, caused by aphids. Aegonychon purpurocaeruleum, Buglossoides arvensis, Lithospermum officinale: Brachycaudus helichrysi

6b Shoot axis usually stunted on one side and distorted, inserted leaves deflected over their tip, ± curled and rolled downwards, deep green close to the froth-covered nymph. Buglossoides arvensis: Philaenus spumarius

Last modified 25.iv.2020