Plant Parasites of Europe

leafminers, galls and fungi

gallers on Laserpitium

Dichotomous table for gallers on Laserpitium

by Hans Roskam

1a On leaves and stems => 4

1b On flowers, inflorescences or fruits => 2

2a Malformations include inflorescences => 3

2b ruit bladder-like swollen, ± reddened, protruding above the partial umbel. Containing an orange-red larva. L. latifolium, prutenicum: Kiefferia pericarpiicola

3a Centre of (partial) umbel or stalk of umbel ± swollen, globular to club-shaped. Gall one-to multi-chambered, inner wall covered with mycelium. Each chamber containing a red larva. L. latifolium, prutenicum, siler: Lasioptera carophila

3b Stalk of partial umbel short. Umbel transformed into an irregular globular structure, sometimes overtopped by some normally developed partial umbels. Larva white. L. latifolium: Macrolabis laserpitii

4a On leaf blades or sheaths of leaves => 8

4b On stems, petioles, -midrib or main veins => 5

5 Bulges with yellowish or brown sori => 6

5b Pale-green bulges of various size with glabrous, vitreous surface. L. halleri, latifolium, peucedanoides: Protomyces macrosporus

6a Bulges bearing aecia => 7

6b Mycelium developing spermogonia and primary uredinia sometimes causes conspicuous swellings coalescing over greater areas, soon covered with brown spores. L. prutenicum: Puccinia angelicae

7a Oblong bulges on stalks of leaflets and leaf veins, or rotund to oblong protruding pads on the leaf blade, usually on the underside. Aecia pustule-shaped, with long, whitish, finely frayed peridium. L. siler: Uromyces graminis

7b Similar swellings caused by a host-specific rust developing countersunk pustule-shaped aecia, with irregularly frayed, glossy white borders. L. archangelica: Puccinia laserpitii

8a On leaf blades => 9

8b eaf sheaths ± discoloured, swollen and disfigured. Larvae white. L. prutenicum: Unidentified gall midge

9a Malformation of large leaf areas => 10

9b Tips of basal leaves undulately distorted, irregularly curved, swollen, tuberculate, eventually often yellow-spotted. Froth-covered nymphs on underside. L. krapfii, latifolium, siler: Trioza apicalis

9c Leaf blades with several upwardly directed groove-like protrusions. L. latifolium: Trioza flavipennis

10a Expanded parts of leaf blade ± deflected downwards, nest-like, curled and swollen bulge-like, darker green. L. latifolium, prutenicum: Philaenus spumarius

10b Expanded parts of leaflets of usually normally unfolded leaves swollen, bladder-like, often slightly paler, upperside soon covered with a whitish-grey layer of asci. L. latifolium: Taphridium umbelliferarum

Last modified 25.iv.2020