Betula pendula, Belgium, prov. Luxembourg, Seloignes, Réserve naturelle de la Fourchinée © Stéphane Claerebout

Betula pendula, Hungary, Kimle, 17.iv.2019 © László Érsek

several galls in a row

old gall with exit opening

opened gall

gall with cocoon inside

cocoon

20.vii.2019, larva in the gall

larva, dorsal view

head and pronotum

larva, ventral view

head and sternum

abdomen end, ventral view

gall

More or less rotund swelling in branches of 3-13 mm diameter, generally at a node; often several adjacent nodes are galled. Larva usually solitary. It is fully grown near the end of the summer, and hibernates in the mine. In spring an exit hole is prepared, closed with silk and camouflaged at the outside with reddish-brown frass. Then a tough, whitish cocoon is made in which pupation takes place. The moths appear in May-June.

host plants

Betulaceae, monophagous

Betula pendula, pubescens.

synonyms

Incurvaria tenuicornis Stainton, 1854.

references

Bowdrey (1988a), Buhr (1964a), Heath & Pelham-Clinton (1983a), Kurz (2016a), Redfern & Shirley (2011a), Roskam (2009a), Vuorinen & Vikberg (2011a).