What's eating my nymphaea 'pygmaea rubra'?

Nymphaea 'Pygmaea Rubra' is threatened primarily by water lily aphids and the water lily beetle. Fish in the pond naturally suppress many pests. In the UK, Canada geese and waterfowl will graze pads. Hand-removal and pond-safe sprays are the main defenses for chemical-free ponds.

Dense colonies of brown-black aphids cluster on pads and flower buds, causing leaf distortion, yellowing, and sooty mold deposits. Knock aphids into the water with a firm jet from a hose — fish will eat them. Avoid insecticides in pond water. Remove heavily infested pads and dispose of them.

Adult beetles and brown larvae skeletonize the upper surface of floating pads, leaving ragged brown streaks and holes that cause pads to rot and sink. Hose larvae off pads into the water for fish to consume. Remove and destroy badly damaged leaves. Keep fish such as goldfish in the pond as a biological check.

Oval leaf cases are cut from pad surfaces and glued together around larvae; feeding creates irregular ragged holes and a flotilla of small oval cases on the water. Remove cases and larvae by hand. Submerging pots temporarily for 24 hours drowns larvae. Fish suppress populations over time.

Ducks, geese, and moorhens tear at pads and flowers; herons wade and trample emerging growth, particularly on small or shallow ponds. Stretch monofilament line or netting above the pond margin. Ensure minimum depth of 45 cm so pads spread beyond the wading reach of most herons.