This willow tree is covered in these insects.
The leaves and the ground around the tree is shiny and sticky from all the aphids excrement.
These dark 'scale insects' coat the lower limbs of a willow and their secretions seem to be attracting hornets.
Found on willow tree, many clusters, did not have hand lens at time
Fresh aphid mummy with Pauesia nigrovaria on a Salix x reichardtii tree.