Hydromyza

Hydromyza (Hydromyza livens) belongs to the order Diptera, family Scathophagidae. This specialized pest is closely associated with aquatic environments and is primarily found in stagnant or slow-moving water bodies where Nymphaeaceae family plants grow.

The primary food source for the larvae are members of the water lily family, specifically yellow water-lily (Nuphar lutea) and white water lily (Nymphaea alba). Adult flies lead a semi-aquatic lifestyle, using the surface of leaves as a platform for feeding and egg-laying.

The biology of the pest is strictly synchronized with the vegetation of its host plants. Females deposit eggs directly into the tissues of the petioles or leaves. Upon hatching, the larvae penetrate the stems, where they undergo all developmental stages, creating characteristic tunnels known as mines. Pupation often occurs within the damaged tissues, after which the cycle repeats.

Damage manifests as mechanical injury to the plant tissue; the larvae intensely feed on the internal cavities of the petioles. This disrupts nutrient transport to the aerial part of the leaf, leading to yellowing, deformation, and premature death of the foliage. During mass outbreaks, this pest can significantly reduce the ornamental value and biological productivity of a pond.

Control measures primarily include agrotechnical and mechanical approaches. It is essential to monitor the condition of the leaves regularly and remove heavily infested plant parts to prevent the emergence of adults and the further spread of the population. The use of chemical insecticides in aquatic environments is strictly limited due to high risks to the ecosystem and fish, so priority is given to biological methods and manual removal.