The winged aphids infest plants in May/June. They bear sexless, wingless larvae which after four casts (approx. 5 days) become sexually mature. One aphid has approx. 25 young. They migrate in autumn to fruit trees (damson, plum and sloe).

Hop aphids are light green with dark stripes and damage plants mainly by sucking the sap (phloem). Depending on their metabolism, they exude honeydew, a sugary fluid which attracts a black fungus.