What is the life habit of horned aphid (gallnut aphid)? What are the functions? Where are they mainly distributed?

The horned aphid is also called the aphid and the gallnut aphid. It is an insect of the aphid genus. In summer, it mainly parasitizes on the compound leaf wings or young leaves of Rhus chinensis. The leaves stabbed by the horned aphid produce irregular tumor-shaped galls called gallnuts. It is a water chestnut.