What's eating my hydrocharis morsus-ranae?

Frogbit, a small free-floating pond plant, is most commonly damaged by the frogbit moth whose larvae mine the leaves, and by aphids clustering on rosettes above the waterline. Snails graze the round pads, and ducks readily eat entire rosettes. Its fast reproductive rate by stolons usually allows populations to recover from moderate grazing and pest pressure.

Larvae cut and roll leaf sections or mine pad tissue; floating leaf cases visible on water surface Remove affected leaves and floating cases; natural predators (parasitic wasps, birds) keep populations in check in established ponds

Dense colonies on the upper surface of floating rosettes; leaves yellow and rosettes shrink Hose off with water to submerge and expose to fish; encourage ladybirds at pond margins

Entire rosettes consumed or shredded; population crashed in ponds with heavy waterfowl pressure Exclude ducks from smaller ponds with netting; maintain healthy stolon spread so plant can recover