What's eating my sparganium erectum?

Branched bur-reed (Sparganium erectum) is grazed heavily by waterfowl — particularly coots, swans, and ducks — which uproot rhizomes and strip foliage. Aphids colonise fresh shoots, and reed beetles can skeletonise leaves. Waterfowl grazing is by far the most damaging threat on garden ponds.

Whole shoots pulled out or bitten off at the waterline; rhizomes uprooted, leaving bare mud patches. Protect new plantings with wire mesh cages or plant inside large, heavy marginal baskets waterfowl cannot tip; establish dense stands which tolerate browsing better.

Sticky, curled young leaves; colonies of olive-green aphids on emergent stems and inflorescences in summer. Knock aphids into the water with a hose so fish consume them; avoid spraying insecticides into pond water.

Longitudinal pale streaks or skeletonised patches on leaves; larvae feed underwater on roots. Tolerate low-level attack in established stands; hand-pick adult beetles; populations rarely cause fatal damage.