Hormaphis betulae (Mordvilko, 1901)

Fig. 15

Diagnosis

Apterae 1–2 mm, pale yellow, circular, flat; older juveniles and adults on secondary host with marginal wax rim. Dioecious. Alternates between witch-hazel Hamamelis (Hamamelidaceae) and birch Betula

( Betulaceae). Anholocyclic in Northern Europe, living on birch. Overwintering in the moss layer of mixed coniferous forests and bogs, and during the cold season seen in moss samples.

Distribution

F.