Plant Parasites of Europe

leafminers, galls and fungi

Seifertia azaleae

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

on Rhododendron

Siefertia azaleae on Rhododendron ponticum

Rhododendron ponticum, Ermelo, Kasteel Staverden © Hans Jonkman

Siefertia azaleae on Rhododendron ponticum



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.


Pycnostysanus azaleae (Peck) Mason 1941.


Many indication suggest the the fungus penetrates the buds 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 of the bud scales.


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 4.xii.2020