Biorhiza pallida (Olivier, 1791)
on Quercus, agamous generation

Quercus robur, Hilversum, ‘t Laer, 30.v.2004 © Jan-Willem Wertwijn

detail

Quercus robur, Belgium, prov. Namur, Viroinval, Vierves-sur-Viroin, 26.v.2016 © Stéphane Claerebout

larva
parasite
Irregular group of fused cells, attached to roots. Individual galls are unicellular.The solitary larva is mature in October of the second year
host plants
Fagaceae, monophagous
Quercus frainetto, lusitanica, petraea, pubescens, pyrenaica, robur.
The reference to Cedrus deodara by Houard (1908a) must be a mistake.
on Quercus, sexual generation

Quercus petraea, Belgium, prov. Namur, Baronville, 13.vi.2006 © Jean-Yves Baugnée

Quercus robur, Enter: section through a young gall, 28.iv.2011 © Arnold Grosscurt

remnants of an old gall

Quercus robur, Castricum, 6.v.2011

at the rear of the gall the bud scales are still present

Quercus robur, Bergen op Zoom, 7.v.2012; young gall

very young gall
em>Quercus robur, Belgium, prov. Antwerp, Laakdal, de Roost, 1.vi.2020 © Carina Van Steenwinkel: larva
pupa
pupa
imago
imago
parasitoid pupa (Torymus ?)
parasite
Large (up to almost 5 cm), ± globular, spongy, multilocular bud gall; mature in May-June.
host plants
Fagaceae, monophagous
Quercus canariensis, cerris, faginea, frainetto, ilex, infectoria & subsp. veneris, lusitanica, petraea, pubescens, pyrenaica, robur, suber.
synonyms
Biorhiza aptera Bosc, 1791.
inquilines
Curculio villosus; Synergus gallaepomiformis.
notes
Houard attributes a voluminous lateral swelling on the branches of Cedrus deodara to B. pallida. This is as incorrect as intriguing: on Cedrus not a single gall is known!
references
Abras, Fassotte, Chandelier & Cavelier (2008a), Andersen & Fjellberg (1977a), Béguinot (2001c, 2002a,e, 2003a, 2006a,c, 2012a), Bellmann (2012a), Blanes-Dalmau, Caballero-López & Pujade-Villar (2017a), Braggion (2013a), Buhr (1965a), Cerasa (2015a), Chinery (2011a), Cogolludo (1921a), Coulianos & Holmåsen (1991a), Dauphin & Aniotsbehere (1997a), Deckert & Deckert (2016a), Eady & Quinlan (1963a), Flügel (2016a), Groom (2011a), Hellrigl (2009a, 2010a, 2012a), Hellrigl & Bodur (2015a), Houard (1908a [“Biorrhiza”]), Ilie & Marinescu (2011a), Karaca & Katılmış (2020a), Katılmış & Kıyak (2008a), Kemal & Koçak (2010a), Kollár (2007a, 2011a), Koops (2013a), Kwast (2012a, 2014a), Lambinon, Carbonnelle & Claerebout (2015a), Lambinon & Romain (2009a), Lambinon, Schneider & Chevin (2003a), Marković (2014a, 2015a), Melika (2006a), Melika, Csóka & Pujade-Villar (2000a), Nieves-Aldrey (2001a), Pujade-Villar, Kwast, Thuroczy & Bellido (2002a), Redfern & Shirley (2011a), Roskam (2009a), Salas-Remón, Llimona, Lozano ao (2015a), Schimitschek (1939a), Shachar, Melika, Inbar & Dorchin (2018a), Stănescu (2009a), Tavares (1905a), Tomasi (2003a, 2012a, 2014a), Williams (2010a).