Mikiola fagi (Hartig, 1839)

on Fagus

Fagus sylvatica, Utrechtse heuvelrug, 5.vii.2021 © Ben van As: gradation

Fagus sylvatica, Hungary, Budapest, János-hegy © László Érsek

two galls

underside of a galled leaf

detail

opened gall

larva

Fagus sylvatica, Bussum: at the left the gall of a male, at right of a female larva

Fagus sylvatica, Elspeet, Kasteel Staverden, 18.vi.2019 © Hans Jonkman: cluster of female galls

Fagus sylvatica, Tilburg

underside

the wall of the very hard gall consists of several layers of high, glassy cells, with an inner lining of much smaller, greenish cells

the floor of the gall room ….

…. is covered by loose, swollen, cells; probably thy form the food for the larva

the gall grows much faster than the larva; therefpore a full grown gall initially contains a minute larve, but later a much larger one, like here

an alaready moribund larva and its small parasitoid

an adult parasitoid, that still was in a shriveled gall

also the occupant of this gall ended badly

gall

When the larva is full grown the gall drops to the grond, and the larva closes the opening with silk. The larva hibernates in the gall and pupates in spring.

host plants

Fagaceae, monophagous

Fagus orientalis, sylvatica, x taurica.

Very rarely also on Castanea.

larva

Fagus sylvatica, Tilburg; larva, ventral

spatula and head of the larva

prosternum with spatula (from Möhn, 1955a)

pupa

Fagus sylvatica, Roggebotsebos © Arnold Grosscurt

notes

The species is abundantly common in the Netherlands. It is the more surprising that, as Redfern & Shirley write, the species seems to have gone extinct in the UK.

Galls mainly high up in the canopy (Kampichler & Teschner, 2002a).

The larvae may be killed within their gall by a strong development of the endophytic fungus Apiognomonia errabunda.

references

Abras, Fassotte, Chandelier & Cavelier (2008a), Barnes (1951a), Béguinot (2001c, 2002e,g, 2005a, 2006a, 2007b, 2012a), Bellmann (2012a), Blanes-Dalmau, Caballero-López & Pujade-Villar (2017a), Bruun (2015a), Buhr (1964b), Cilbircioğlu & Ünal (2009a), Cogolludo (1921a), Coulianos & Holmåsen (1991a), Dauphin & Aniotsbehere (1997a), Dziurzynski (1961a,b), Gagné (2010a), Groom (2011a), Hellrigl (2006a), Houard (1908a), Ilie & Marinescu (2011a), Kampichler & Teschner (2002a), Kieffer (1901a), Kollár (2011a), Koops (2013a), Lambinon, Carbonnelle & Claerebout (2015a), Lambinon & Romain (2009a), Lambinon, Schneider & Feitz (2001b), Lehmann & Hannover (2016a), Mirumian (2011a). Möhn (1955a), Nieves Aldrey (1998a), Pujade i Villar (1990a), Redfern & Shirley (2011a), Roques, Cleary, Matsiakh & Eschem (2017a), Roskam (2009a), Roskam & Carbonnelle (2015a), Seidel (1957a), Simova-Tošić & Skuhravá (2001a), Simova-Tošić, Skuhravá & Skuhravý (1999a, 2000a, 2004a, 2007a), Skrzypczyńska (2007a), Skuhravá (2006a), Skuhravá, Bayram, Çam ao (2005a), Skuhravá, Karimpour, Sadeghi ao (2014a), Skuhravá & Skuhravý (1988a, 1992b, 1994a, 1997a,b, 1999a,b, 2005c, 2006a, 2007a, 2008a, 2009b, 2010a), Skuhravá, Skuhravý, Blasco-Zumeta & Pujade-Villar (2006a), Skuhravá, Skuhravý & Buhr (2013a), Skuhravá, Skuhravý, Dauphin & Coutin (2005a), Skuhravá, Skuhravý, Dončev & Dimitrova (1991a, 1992a), Skuhravá, Skuhravý &; Hellrigl (2001a), Skuhravá, Skuhravý & Jørgensen (2006a), Skuhravá, Skuhravý & Massa (2007a), Skuhravá, Skuhravý & Meyer (2014a), Skuhravá, Skuhravý & Neacsu (1972a), Skuhravá, Skuhravý, Skrzypczyńska & Szadziewski (2008a), Stănescu (2009a), Tomasi (2003a, 2014a), Unal & Akkuzu (2009a).