What's eating my zizania latifolia?

Zizania latifolia (Manchurian wild rice) is an aquatic grass grown for its edible shoots. The primary damage in cultivation comes from aphids on young growth, waterfowl grazing emerging stems, and stem-boring insects in warmer regions. Slugs attack shoots at the water margin during early spring growth.

Dense colonies on young shoots and leaves cause distortion, yellowing, and sooty mould. Knock off with a strong water jet; introduce ladybirds or lacewings; avoid broad-spectrum insecticides near water.

Graze emerging shoots aggressively, often stripping plants to water level. Protect young plants with wire cages or netting until established; deter birds with floating barriers.

Larvae tunnel into culms causing wilting, dead-heart symptoms, and lodging of stems. Remove and destroy infested stems promptly; maintain healthy plant vigour with adequate nutrition and water depth.