Problem: Aphids (Lily)
Several different species of this common insect feed on lilies. Aphids cause their damage by sucking plant sap; this feeding produces leaf curling, yellowing, and distortion. The aphid is unable to digest fully all the sugar in the plant sap, and it excretes the excess in a fluid called honeydew. The honeydew often drops onto the leaves below. Ants feed on this sticky substance and are often present where there is an aphid infestation. Aphids can also spread viral diseases. In the process of feeding, certain aphids can infect lilies with mosaic virus disease.
Apply an insecticide labeled for aphids, following label directions. In the fall, clean up plant debris that might harbor aphid eggs.