Andricus rhyzomae (Hartig, 1843)
on Quercus, agamous generation
galls (from Houard, 1908a)
Quercus robur (root collar of a young tree), Drenthe, Beilen, Schepping in Holthe, 10.vii.2021 © Eef Arnolds
Quercus robur, Elspeet, landgoed Staverden © Hans Jonkman: young, still fleshy gall
Quercus robur, De Schipborg, Aa en Hunze © Arnold Grosscurt
two tiny galls
Galls, mostly several together, on the bark mainly near the base of a trunk. Fresh gall are semi-globular, 2-5 mm high, and have a fleshy red outer layer. After this has been eroded away, a low, woody, truncate cone remains with a radial striation on its base, and a large exit opening at its tip.
Quercus lusitanica, petraea, pubescens, pyrenaica, robur.
for over more than half century is is assumed that A. rhyzomae is the agamous generation of Andricus testaceipes, but experimental proof is still being awaited. In case the synonymy might be proven, then testaceipes is the oldest, hence valid, name.
Similarly, it is broadly assumed that Andricus nodifex is the sexual generation of rhyzomae; here also experimental confirmation is waiting.
Andricus rhizomae (Schenck, 1863).
Buhr (1965a), Cerasa (2015a), Dauphin & Aniotsbehere (1997a), Eady & Quinlan (1963a), Hellrigl (2009a), Hellrigl & Bodur (2015a), Houard (1908a), Kwast (2014a), Meika (2006a), Melika, Csóka & Pujade-Villar (2000a), Redfern & Shirley (2011a), Roskam (2009a), Tavares (1905a), Tomasi (2014a), Williams (2010a).