What's eating my arrowhead 'kuwai'?

Arrowhead 'Kuwai' is an aquatic/marginal edible grown in shallow water or wet soil. Leaf beetles and aphids attack foliage; waterfowl and muskrats eat tubers and foliage directly. The aquatic setting limits many common garden pests but opens up larger vertebrate grazers as the key threat.

Adults skeletonise leaf surfaces; larvae feed on roots and submerged stem tissue; significant defoliation in warm summers reduces tuber yield. Hand-pick adults; neem oil spray on above-water foliage; physical barriers (fine netting over young plants in tubs) reduce adult colonisation.

Dense colonies on leaf surfaces and petioles; honeydew coats leaves; heavy infestations distort and yellow foliage. Knock into water with a firm water jet — fish will consume fallen aphids; insecticidal soap applied to dry foliage (keep off water surface).

Ducks and geese graze leaves; muskrats excavate and eat the edible tubers, often removing whole clumps overnight. Net or cage individual container plantings; floating row covers; fencing around pond margins in areas with high muskrat pressure.