Neuroterus quercusbaccarum (Linnaeus, 1758)
on Quercus robur, agamous generation
Quercus robur, Duin en Kruidberg, 30.vii.2006: full grown gall, underside of the leaf
group of somewhat younger galls
same group, seen from the upperside (lighted from behind)
stellate hairs on the surface of a fully developed gall
very young gall
Quercus spec., North Macedonia, National Park Galičica (Resen), oak forest, 1100 m a.s.l., 30.vii.2019 © Cor Zonneveld
Quercus petraea, Hungary, Kimle, 12.viii.2017 © László Érsek: transverse section
Quercus petraea, Hungary, Budapest, Hűvösvölgy, 17.ix.2018 © László Érsek
from the side
opened gall
larva in the gall
larva
gall
The gall is attached to the leaf by means of a short central stalk. Galls in July till October, mature in August.
Belgium, prov. Namur, Beauraing, RN Rend Peine © Stéphane Claerebout: the larva hibernates in the fallen gall; picture taken in April
underside
host plants
Fagaceae, monophagous
Quercus canariensis, cerris, congesta, dalechampii, frainetto, x haynaldiana, infectoria & subsp. veneris, lusitanica, macranthera, petraea & subsp. pinnatiloba, pubescens, robur & subsp. pedunculiflora, trijana.
on Quercus robur, sexual generation
Quercus robur, Hungary, Kimle, 6.v.2016 © László Érsek
failed imago with parasitoid larva
Quercus pubescens, France, dép. Val d’Oise, Saint-Leu-la-Forêt, 2.v.2021 © Pierre Duhem
same leaf, upper side
Quercus robur, Nieuwendam: young gall in a male catkin
Quercus robur, Biddinghuizen, Spijk- en Bremerbergbos © Hans Jonkman
Quercus robur, Enter © Arnold Grosscurt
Quercus robur, Dwingelderveld; the currant galls of the sexual generation are formed also on leaves; they are broadly attached.
The “currants” drop to the ground; when they are opened the pupae appear already far developed, often already vacated (early May).
The adult leaves the gall through a small opening (left); at right a parasitised pupa
Quercus robur, Tynaarloo © Arnold Grosscurt: another time the leaf-inhabiting form of the currant gall; at the upperside of the leaf the broad attachment of the gall is clearly visible.
the gall seen from below
vertical section: one gall chamber
Quercus robur, Biddinghuizen, Spijk- en Bremerbergbos, 28.v.2016 © Hans Jonkman: cluster of galls
the leaf around the gall has been completely eaten away. This demonstrates that the gall for its development attract nutrients not so much from the leaf as from the plant as a whole, through the leaf venation/
gall
Smooth, juicy, 4-8mm sized, berry-like galls on the male catkins, often several together. Less often on the leaves, then mostly at the underside, with a low translucent swelling at the upper side. There is no real inner gall. Galls in May-June. Ripe gall turn brown and drop to the ground, sometimes forming a dense carpet. Parasitised galls turn brown later and remain longer on the tree.
host plants
Fagaceae, monophagous
Quercus cerris, frainetto, infectoria & subsp. veneris, petraea, pubescens, robur.
synonyms
Neuroterus baccarum Blanchard, 1849; N. histrio Kieffer, 1901; N. intermedius Tavares, 1916; N. lenticularis Olivier, 1781; N. quercusbaccarum hispanicus Tavares, 1916.
inquilines
In the agamous generation often the inquiline larvae of the gall midge Parallelodiplosis galliperda can be found in the space between the gall disk and the leaf blade. Furthermore Synergus gallaepomiformis, pallipes.
parasitoids, predators
Aulogymnus arsames, gallarum; Eupelmus urozonus; Eurytoma brunniventris; Mesopolobus dubius, fasciiventris, sericeus, tibialis; Ormyrus orientalis, pomaceus; Pediobius lysis; Sycophila biguttata; Torymus auratus, flavipes.
references
Abras, Fassotte, Chandelier & Cavelier (2008a), Andersen & Fjellberg (1977a), Askew (1961b), Béguinot (2001c, 2002a,d,e,f,g,h, 2003a,b, 2005a, 2006a,c, 2007b, 2012a), Bellmann (2012a), Blanes-Dalmau, Caballero-López & Pujade-Villar (2017a), Buhr (1965a), Cerasa (2015a), Chinery (2011a), Cogolludo (1921a), Coulianos & Holmåsen (1991a), Dauphin & Aniotsbehere (1997a), Deckert & Deckert (2016a), Dietrich (2016a), Eady & Quinlan (1963a), Ecott (2012a), Flügel (2016a), Gençer (2014a), Gómez, Hernández Nieves, Garrido Torres, ao (2006a), Groom (2011a), Hellrigl (2009a, 2010a), Hellrigl & Bodur (2015a), Houard (1908a), Ilie & Marinescu (2011a), Karaca & Katılmış (2020a), Kampichler & Teschner (2002a), Katılmış & Kıyak (2008a), Kollár (2007a, 2011a), Koops (2013a), Kwast (2012a, 2014a), Lambinon, Carbonnelle & Claerebout (2015a), Lambinon & Romain (2009a), Lambinon, Schneider & Chevin (2003a), Lehmann & Hannover (2016a), Marković (2014a, 2015a), Melika (2006a), Melika, Csóka & Pujade-Villar (2000a), Mete & Demirsoy (2012a), Nieves-Aldrey (1984b, 1998a, 2001a), Nieves-Aldrey, Gómez, Hernández Nieves & Lobo (2006a), Pellizzari (2010a), Plantard & Hochberg (1998a), Plantard, Rasplus & Hochberg (1996a), Pujade-Villar (2005b), Redfern & Shirley (2011a), Roques, Cleary, Matsiakh & Eschem (2017a), Roskam (2009a), Schimitschek (1939a), Shachar, Melika, Inbar & Dorchin (2018a), Stănescu (2009a), Sylvén (1960a), Tavares (1905a), Tomasi (2012a, 2014a), Vilarrubia Garet (1956a), Williams (2010a).