This is a small genus that is associated with Prunus as primary hosts and Humulus and Cannabis as secondary hosts. The only species in North America are introduced, one a pest of Prunus and hops, the other a pest of Cannabis. I have photos of only one of these.
Phorodon humuli (Schrank)
This aphid is one of more serious pests of hops in North America, and is very widespread. I commonly see it in the spring on ornamental plums in landscapes of business districts of cities and towns.