Knapweed Aphids

Knapweed Aphids

Observation - Knapweed Aphids - UK and Ireland. Description: There were hundreds of these tiny black insects on black knotweed plants. Pool and river nearby.

There were hundreds of these tiny and mainly black insects on black knapweed plants. Some insects were brownish and I'm not sure if they are all the same spicies or not. Pool and river nearby.