What's eating my myriophyllum spicatum?

Eurasian watermilfoil is a vigorous aquatic weed; in naturalistic ponds its primary pests are the milfoil weevil and milfoil moth, both used in biocontrol. Waterfowl graze the feathery stems. In ornamental settings, heavy waterfowl browsing and aphids on emergent tips are the main concerns. Robust growth usually outcompetes light damage.

Larvae mine stems causing fragmentation and die-back; used deliberately as biocontrol against invasive stands In garden ponds, manage by physical removal of excess plant matter; weevil rarely a problem in ornamental settings at low density

Clusters on emergent flower spikes and stem tips above water; yellowing and honeydew deposits Knock off with water jet; encourage natural aphid predators around the pond margin; remove infested tips

Feathery stems pulled apart and consumed; large patches cleared in open water Physical barriers or netting in small ponds; accept grazing in wildlife ponds where plant regrows rapidly