Willow emerald damselfly

The Willow emerald damselfly (lat. Lestes viridis) belongs to the order Odonata and the family Lestidae. While most damselflies are considered beneficial predators, this species can act as a plant pest under specific agricultural conditions due to its unique egg-laying behavior within plant tissues.

This pest primarily affects woody plants and shrubs, as well as certain vegetable and grain crops located near water bodies. The main damage occurs during oviposition, when the female makes incisions in the bark of young twigs or plant stems to deposit its eggs.

The life cycle consists of an egg stage, a nymph (larval) stage, and an adult stage. The larvae develop in stagnant or slow-moving water and act as active predators. Adults emerge in the second half of summer, followed by mating and egg-laying in the stems of riparian vegetation.

Damage is characterized by mechanical wounds on stems, which trigger necrosis, shoot wilting, and a decrease in the plant's overall resistance. These wounds often become entry points for secondary infections caused by pathogenic fungi and bacteria, significantly increasing the total damage to the crop.

Protection measures focus on agrotechnical methods, including the timely removal of weeds and riparian vegetation where females lay their eggs. In cases of massive outbreaks, the application of contact-stomach insecticides is recommended, alongside monitoring moisture levels and crop density in the fields.