What's eating my salvinia natans?

Salvinia natans is a floating aquatic fern for ponds and indoor aquaria. Aphids are the most common pest, clustering on the upper fronds. Water snails rasp fronds in outdoor settings, and pond fish can graze mats bare. Overly dense growth also creates conditions where anaerobic decay rather than pests becomes the main threat.

Dense colonies on frond surfaces cause yellowing and reduced vigour; honeydew fosters fungal growth. Rinse fronds with clean water, remove affected sections, or introduce aphid predators such as hoverfly larvae near outdoor ponds.

Snails rasp irregular holes in fronds, particularly in outdoor container ponds. Hand-pick at dusk; place a lettuce leaf as a trap and remove it with snails each morning.

Goldfish and koi consume entire floating mats rapidly. Separate Salvinia into a fish-free zone or float it in a mesh cage within the pond.