Waterlilly aphid
Rhopalosiphum nymphaeae
The water lily aphid can be a pest of aquatic ornamentals such as Nyphar lutea and Nymphae alba. It causes considerable distortion of stems and foliage and also discolours the flowers. Control is by forcibly spraying with water to dislodge and drown aphids. Insecticides should not be used as they are toxic to fish and pond life. On fruit trees dense colonies may develop in spring on young shoots causing noticeable distortion of the foliage. Such colonies usually die out by June.