Apterae of Schizaphis scirpi are shiny dark bronze-brown to reddish brown or blackish with a  body length of 1.5 to 2.8 mm.  Fur further details see the 'Further Information' link below.

Please provide good close up images and state the host plant.

Wetland areas where Bulrush or Bur-reed species occur.

Summer

Schizaphis scirpi lives in ant-attended colonies at the leaf-bases of Bulrush and Bur-reed species, also using other water plants at times.  They do not host alternate.

True status is difficult to determine as it does not seem to be well recorded in Britain.

Rarely recorded in Leicestershire and Rutland.

https://influentialpoints.com/Gallery/Schizaphis_scirpi_bulrush_aphid.htm