What's eating my least yellow water lily?

Least Yellow Water Lily shares the same aquatic pest complex as other Nuphar species. The water lily leaf beetle scrapes floating leaves, water lily aphids cluster on stems and pads, and pond moth larvae mine into petioles. Being a smaller, rarer species it is also vulnerable to waterfowl and muskrat browsing, which can quickly overwhelm compact plantings.

Grubs and adults scrape away the upper surface of floating pads, leaving slots and holes; leaves rot and sink when badly damaged Brush adults and larvae off leaf surfaces into the water; remove the most damaged pads; no practical insecticide safe for pond use

Black or green colonies on pads and stems, particularly in warm spells; sticky honeydew and sooty mould reduce photosynthesis Hose aphids off leaf pads into the water; control overwintering eggs on adjacent plum or blackthorn trees; pond fish consume dislodged aphids

Larvae cut and roll leaf pieces for shelter or mine into petioles; irregular leaf damage and severed petioles visible at the surface Hand-remove visible rolled leaf shelters; tolerate low-level damage in naturalistic ponds; no practical safe insecticide for pond environments