Cochylis nana (Haworth, 1811)
the larva, a caterpillar, lives during the summer in a female catkin, that may become somewhat disfigured; in autumn pupation follows in a bark fissure.
Betula pendula, pubescens.
Acornutia, Conchylis, nana.
Bradley, Tremewan & Smith (1973), Buhr (1964a), Disqué (1905a), Hancock & Bland (2015b).