Water lily midge

The water lily midge (Chironomus nymphaeae) is a dipteran insect belonging to the Chironomidae family. While many midges are harmless or beneficial, this specific species is recognized as a pest in aquaculture and decorative gardening, specializing in aquatic plants.

This pest primarily infests members of the Nymphaeaceae family, specifically water lilies. The larvae feed directly on the plant tissue, causing significant stress to the host plants and reducing their aesthetic value within garden ponds and natural water bodies.

The life cycle of the midge consists of egg, larva, pupa, and adult stages. The female deposits eggs on the water surface or the leaves. Upon hatching, the larvae construct small shelters or cases out of debris and silk, tethering them to the underside of the floating leaves to feed securely.

Damage is characterized by the presence of irregular galleries or tunnels within the leaf tissue, often referred to as leaf mining. This feeding behavior results in localized necrosis, leaf chlorosis, and eventual decay of the leaf blade, which can eventually lead to the loss of entire leaves in severe infestations.

To effectively manage Chironomus nymphaeae, a multi-faceted approach is recommended:

• Manual removal and destruction of heavily infested leaves.
• Introducing fish species that prey on midge larvae.
• Improving water circulation and aeration to disrupt the breeding environment.
• Utilizing biological larvicides that are safe for non-target aquatic organisms.