Tracya hydrocharidis Lagerheim, 1902

on Hydrocharis

Hydrocharis morsus-ranae, Belgium, prov. Limbourg, Gelinden 11.viii.2021 © Carina Van Steenwinkel: beginning infestation, recognisable as pale areas at the underside of the leaf.

the finale stage: the leaf tissue is decomposing, releasing the spore balls

spore balls

Hydrocharis morsus-ranae, Belgium, prov. Antwerp, Laakdal, de Roost, 5.ix.2021 © Carina Van Steenwinkel: groups of spore balls in an as yet intact leaf

detail

crushed spore balls, showing the outer layer of spores.

surface of the spore layer

side view of the spore layer

gall

ill-delimited, up to some cm large, pale to brown leaf spots; embedded in the tissue up to 0.3 mm large spore balls. A spore ball consists of a globular, three-dimensional network of irregular filaments, with at its outside a closed, single layer of prismatic spores.

host plants

Hydrocharitaceae, monophagous

Hydrocharis morsus-ranae.

references

Brandenburger (1985a: 701), Buhr (1964b), Gönczö & Révay (1981a), Klenke & Scholler (2015a), Scholz & Scholz (2013a), Spooner & Leon (2006a), Van Steenwinkel, Fraiture & Vanderweyen (2022a), Tomasi (2014a), Vánky (1981a, 1994a), Vánky & Abbasi (2013a).