Aphids are tiny, pear-shaped, soft-bodied insects and come in a wide variety of colours.
The great majority of adult aphids are wingless. Males may occasionally have wings, as well as females that need to migrate to new host plants.
Aphids have a tail-like protrusion, or cauda, at the tip of the abdomen. This directs the secretions of a sweet substance called honeydew from their rectal apertures. Many species also have two cornicles – tubes resembling tailpipes – extending from the abdomen.