Andricus quercuscalicis (Burgsdorf, 1783)
knopper gall
on Quercus, agamous generation
Quercus robur, Hungary, Budapest, arboretum, 15.vii.2017 © László Érsek
same gall, seen from the peduncle
sliced
Quercus robur, Hungary, Budapest, Hűvösvölgy, 24.viii.2017 © László Érsek: inner gall with larva
larve
this apparently mouldy inner gall contained a living larva
Quercus robur, Belgium, prov. Namur, Hour, 11.viii.2007 © Jean-Yves Baugnée
Quercus robur, Zeewolde, Harderbos, 23.vii.2016 © Hans Jonkman: young galls, mid July
slightly older
same gall from above
Quercus robur, Biddinghuizen, Spijkbos, 30.vii.2015 © Hans Jonkman: young gall
Quercus robur, Zeewolde, Harderbos, 6.viii.2015 © Hans Jonkman: the gall starts to overgrow the acorn
here the acorn is completely engulfed
gall
the gall develops from the inside of the cupula. Young gall can easily be mistaken for Andricus grossularia. in cross section however that is a multilocular galling of the acorn itself. The development of the knopper gall is a completely different one.
host plants
Fagaceae, monophagous
Quercus x haynaldiana, petraea, pubescens, robur.
on Quercus, sexual generation
Quercus cerris, gall (from Houard, 1908a)
Quercus cerris, Dronten © Arnold Grosscurt. (The large galls are of Andricus grossulariae.)
gall
Ovoid gall, 2.5 mm high, derived from one, strongly enlarged locule; remnants of the other locule are visible at the side of the gall.
host plants
Fagaceae, narrowly monophagous
Quercus cerris, suber.
synonyms
Cynips quercuscalicis; C. calicis Hartig, 1843, Andricus beyerincki / beijerincki Trotter, 1899; A. cerri Beijerinck, 1885; Andricus flavicornis Schenck, 1863.
parasitoids, predators
Cecidostiba adana; Eupelmus barai, messene, urozonus; Ormyrus nitidulus, pomaceus.
notes
The species is found also in regions where Quercus cerris does not naturally occur; it even seems to be on the increase there. It is not clear whether the sexual generation is only facultative, and thus may be skipped, or that the relatively few artificially planted cerris trees are sufficient to maintain the population. See Kofler & Zwander (2009a) and other on this question.
references
Béguinot (2006c), Bellmann (2012a), Blanes-Dalmau, Caballero-López & Pujade-Villar (2017a), Buhr (1965a), Burton, Carbonnelle, Ellis & Schneider (2019a), Cerasa (2015a), Chinery (2011a), Cogolludo (1921a), von Dalla Torre (1893a), Dauphin & Aniotsbehere (1997a), Ellis (2005a), Fusu (2017a), Groom (2011a), Hellrigl (2009a, 2010a) Hellrigl & Bodur (2015a), Houard (1908a), Katılmış & Kıyak (2008a), Kemal & Koçak (2010a), Kofler & Zwander (2009a), Kollár (2007a, 2011a), Koops (2013a), Kwast (2012a, 2014a), Lambinon, Carbonnelle & Claerebout (2015a), Lambinon Schneider & Feitz (2012a), Lehmann & Hannover (2016a), Marković (2014a), Melika (2006a), Melika, Csóka & Pujade-Villar (2000a), Pellizzari (2010b), Redfern & Shirley (2011a), Roques, Cleary, Matsiakh & Eschem (2017a), Roskam (2009a), Schneider (2016a), Stojanova (2005a), Tavares (1905a), Tomasi (2014a), Williams (2010a).