Plant Parasites of Europe

leafminers, galls and fungi

Seifertia azaleae

Seifertia azaleae (Peck) Partridge & Morgan-Jones, 2002

on Rhododendron

Seifertia azaleae on Rhododendron ponticum

Rhododendron ponticum, Belgium, prov. Limbourg, Beverlo, Einderse Beemden, 12.iii.2022 © Carina Van Steenwinkel

Seifertia azaleae on Rhododendron ponticum

same leaf, underzijde

Seifertia azaleae on Rhododendron ponticum

with a hand lense the synnemata (stiff bundles of hypha) are visible.

Seifertia azaleae on Rhododendron ponticum

more strongly magnified

Seifertia azaleae on Rhododendron ponticum: synnema

young synnema

Seifertia azaleae on Rhododendron ponticum

tip, with conidia

Seifertia azaleae on Rhododendron ponticum

in older synnemata the conidia are formed in branching chains

Seifertia azaleae on Rhododendron ponticum

detail

Seifertia azaleae on Rhododendron ponticum: conidia

isolated conidia

Siefertia azaleae on Rhododendron ponticum

Rhododendron ponticum, Ermelo, Kasteel Staverden © Hans Jonkman

Siefertia azaleae on Rhododendron ponticum

detail

gall

The flower and leaf buds wither and finally die off. Their surface is covered by several mm high, erect, black “hairs”, in fact bundels of hyphae (“synnemata”) that apically bear a tuft of chains of conidia.

host plants

Ericaceae, monophagous

Rhododendron catawbiense, ponticum.

Found by Beenken & Senn-Irlet also on the native Rhododendron ferrugineum.

synonyms

Pycnostysanus azaleae (Peck) Mason 1941.

notes

Many indication suggest the the fungus penetrates the plant via wounds made the the cicada Graphocephala fennahi. This conspicuous, strikingly coloured insect is an invasive that relatively recently has been introduced into Europe. The female deposits her yellow, pear-shaped eggs in a semicircle under the epidermis.

references

Beenken & Senn-Irlet (2016a), Endrestøl (2017a), Ferracini, Gilardi & Alma (2003a), Kruse (2019a), Laister (2008a), Seifert, Hughes, Boulay & Louis-Seize (2007a), Špryňar (2005a), Termorshuizen (2004a).

Last modified 17.iii.2022