Hamamelistes betulinus

Birch blister aphid

Description

Birch blister aphid Hamamelistes betulinus is primarily found on the undersides of leaves of downy birch (Betula pubescens). However, they can also be found on silver birch (Betula pendula) and occasionally on grey alder (Alnus incana). In Europe and northern Asia, the birch blister aphid Hamamelistes betulinus does not produce sexual forms and does not undergo host alternation. It feeds on the undersides of birch leaves and its feeding activity causes pale yellowish blisters to develop on the upper surfaces of the leaves. During winter, the aphid overwinters as first instar larvae on the twigs of the birch trees. In Japan, however, there is a host alternation observed between Hamamelistes betulinus and its primary host, Hamamelis. Overall, Hamamelistes betulinus displays different reproductive strategies and host preferences depending on its geographical location, with the presence or absence of host alternation playing a significant role in its life cycle. There are many other aphids live on birch.