Andricus quercusramuli (Linnaeus, 1761)
cottonwool gall wasp
on Quercus, agamous generation

Quercus robur, UK, Suffolk, Kelsale, 8.xi.2018 © Jeremy Bowdrey

Quercus robur (from Houard, 1908a)
gall
Egg-shaped, thin-walled bud gall with a distinct acute tip, 3-5 mm long, for c. 2/3 hidden by the bud scales. The smooth outer wall is succulent; when the gall matures the wall dries, becomes whitish and acquires length grooves. Galls in September-October; mature galls drop to the ground.
host plants
Fagaceae, monophagous
Quercus petraea, pubescens, robur.
on Quercus, sexual generation

Quercus petraea, Hungary, Kimle, 24.v.2018 © László Érsek

fresh galls

other side

individual gall chambers

a single gall chamber, with larva

detail

larve

older galls (same tree, 24.v.2018)

detail

Quercus pubescens, Spain, Catalunya, prov. Barcelona, Palau Solià i Plegamans © Jordi Montobbio

Quercus pubescens, Spain, Catalunya, prov. Barcelona, Cerdanyola: split gall © Jordi Montobbio

Quercus robur, Wijk aan Zee, 30.v.2019 © Cor Zonneveld

detail
parasite
Galling of a male catkin. Attached to the petiole of a catkin is a group of 1-20 cells, each 1-2 mm in diameter, each with a mass of white hairs, altogether creating an almost walnut sized white globe. The galls are mature in June, but galled catkins remain on the tree until as late as August.
host plants
Fagaceae, monophagous
Quercus faginea, frainetto, lusitanica, petraea, pubescens, pyrenaica, robur.
synonyms
Andricus ramuli Schenck, 1863; A. autumnalis Hartig, 1840; A. trifasciata Kieffer, 1901.
references
Béguinot (2000b), Bellido, Ros-Farré & Pujade-Villar (2003a), Bellmann (212a), Blanes-Dalmau, Caballero-López & Pujade-Villar (2017a), Buhr (1965a), Cerasa (2015a), Cerasa, lo Verde & Massa (2014a), Chinery (2011a), Cogolludo (1921a), Coulianos & Holmåsen (1991a), Dauphin & Aniotsbehere (1997a), Eady & Quinlan (1963a), Ecott (2012a), Hellrigl (2009a), Hellrigl & Bodur (2015a), Houard (1908a), Katılmış & Kıyak (2008a), Kemal & Koçak (2010a), Koops (2013a), Kwast (2014a), Meika (2006a), Melika, Csóka & Pujade-Villar (2000a), Nieves-Aldrey (1983a, 1998a, 2001a), Redfern & Shirley (2011a), Roskam (2009a), Tavares (1905a), Tomasi (2003a, 2012a, 2014a), Wiebes-Rijks (1976a), Williams (2010a).