Brown lacewing

Hemerobius stigma belongs to the order Neuroptera and the family Hemerobiidae. While many members of this family are considered beneficial predators in various ecosystems, this specific species is frequently monitored due to its association with coniferous trees, where its feeding habits can have a detrimental impact on host vigor.

The primary host plants for this insect include various species of pines and spruces. The pest typically inhabits the bark and twigs, utilizing the tree's resources for its development. Because it settles on coniferous forests and ornamental plantations, it requires careful management to prevent localized damage and stress to trees.

The biological development follows a complete metamorphosis: egg, three larval instars, pupa, and adult. The insect usually overwinters as an adult in sheltered locations such as bark crevices. The number of generations per year is highly dependent on climate conditions and regional temperature patterns, influencing the peak population outbreaks.

Damage caused by this pest includes feeding lesions on the bark and phloem tissues, which can lead to localized necrosis. These lesions act as entry points for secondary pathogens, such as fungal infections or wood-boring beetles. Consequently, heavily infested trees may exhibit weakened growth, needle yellowing, and decreased resilience against environmental stressors.

Management and control strategies involve maintaining forest hygiene, such as removing dead or dying branches that harbor overwintering populations. Biological control agents should be considered to maintain natural balance. In cases of significant economic damage, systemic or contact insecticides may be applied, ensuring that treatments are timed during the most susceptible stages of the pest's lifecycle.