The body length of Cavariella aegopodii apterae is 1.5 to 2.8 mm, they are greenish or reddish. The alate of Cavariella aegopodii has a central black patch on the abdominal dorsum, and a dark cauda and siphunculi.

Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used and describe the size and identifying characters. Please state the host plant when adding your record.Wherever the host plants occur.

Wherever the host plants occur.

When the host plants are in leaf.

The Willow-carrot aphid host alternates from Willows (Salix sp.) to umbellifers (Apiaceae). The preferred primary hosts are Hybrid Crack-willow (Salix fragilis) and White Willow (Salix alba). Preferred secondary hosts are cultivated umbellifers such as Carrots (Daucus carota) and Fennel (Foeniculum vulgare) as well as several wild umbellifers.

Status in Britain is difficult to determine due to lack of records, but this species is believed to be widespread and fairly frequent.

Status in Leicestershire and Rutland not known.

https://influentialpoints.com/Gallery/Cavariella_aegopodii_Willow-carrot_aphid.htm