Neuroterus quercusbaccarum (Linnaeus, 1758)

on Quercus robur, agamous generation

Neuroterus quercusbaccarum gall

Quercus robur, Duin en Kruidberg: full grown gall, underside of the leaf

Neuroterus quercusbaccarum galls

group of somewhat younger galls

Neuroterus quercusbaccarum galls

same group, seen from the upperside (lighted from behind)

stellate hairs on the surface of a fully developed gall

very young gall

Neuroterus quercusbaccarum: gall on Quercus petraea

Quercus petraea, Hungary, Kimle, 12.viii.2017 © László Érsek: transverse section

Neuroterus quercusbaccarum: gall on Quercus petraea

Quercus petraea, Hungary, Budapest, Hűvösvölgy, 17.ix.2018 © László Érsek

Neuroterus quercusbaccarum: gall on Quercus petraea

from the side

Neuroterus quercusbaccarum: gall on Quercus petraea

opened gall

Neuroterus quercusbaccarum: gall on Quercus petraea

larva in the gall

Neuroterus quercusbaccarum: larva

larva

gall

The gall is attached to the leaf blad by means of a short central stalk. Galls in July till October, mature in August.

Neuroterus quercusbaccarum: hibernated gall

Belgium, prov. Namur, Beauraing, RN Rend Peine © Stéphane Claerebout: the larva hibernates in the fallen gall; picture taken in April

Neuroterus quercusbaccarum: hibernated gall

underside

hostplants

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

Neuroterus quercusbaccarum FM

Quercus robur, Nieuwendam: young gall in a male catkin

Neuroterus quercusbaccarum: sexual generation gall

Quercus robur, Biddinghuizen, Spijk- en Bremerbergbos © Hans Jonkman

Neuroterus quercusbaccarum FM gall

Quercus robur, Enter © Arnold Grosscurt

Neuroterus quercusbaccarum FMNeuroterus quercusbaccarum FM

Quercus robur, Dwingelderveld; the currant galls of the sexual generation are formed also on leaves; they are broadly attached.

Neuroterus quercusbaccarumNeuroterus quercusbaccarum

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

Neuroterus quercusbaccarum FM gall on Quercus robur

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.

Neuroterus quercusbaccarum FM gall on Quercus robur

the gall seen from below

Neuroterus quercusbaccarum FM gall on Quercus robur

vertical section: one gall chamber

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.

hostplants

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.

references

Abras, Fassotte, Chandelier & Cavelier (2008a), Béguinot (2001c, 2002a,d,e,f,g,h, 2003a,b, 2005a, 2006a,c, 2007b, 2012a), Bellmann (2012a), Buhr (1965a), Ceresa (2015a), Chinery (2011a), Cogolludo (1921a), Coulianos & Holmåsen (1991a), Dauphin & Aniotsbehere (1997a), Deckert & Deckert (2016a), Dietrich (2016a), Eady & Quinlan (1963a), Ecott (2012a), Flügel (2016a), Groom (2011a), Hellrigl (2009a, 2010a), Hellrigl & Bodur (2015a), Houard (1908a), Ilie & Marinescu (2011a), 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 (1998a, 2001a), Nieves-Aldrey, Gómez, Hernández Nieves & Lobo (2006a), Pellizzari (2010a), Pujade-Villar (2005b), Redfern & Shirley (2011a), Roskam (2009a), Shachar, Melika, Inbar & Dorchin (2018a), Stănescu (2009a), Sylvén (1960a), Tomasi (2012a, 2014a), Vilarrubia Garet (1956a), Williams (2010a).

mod 5.xii.2018