Poplar Lutestring

The Poplar Lutestring (scientific name Tethea or) is a moth species belonging to the family Drepanidae, subfamily Thyatirinae. It is a common insect in the temperate regions of Europe and Asia, often found in deciduous forests, parks, and tree nurseries where its host plants are present.

The primary host plants for this pest include trees from the genus Populus, specifically aspen and various poplar cultivars. The larvae are specialized feeders on foliage, and their presence is particularly significant in young plantations where severe defoliation can lead to stunted development and economic loss.

The life cycle consists of one or two generations per year depending on the climate. Adults emerge in late spring and are nocturnal, flying during the night. Females lay eggs singly on the undersides of leaves. The larvae go through five instars before pupating within a silken cocoon folded inside a leaf or tucked into bark crevices.

Larval feeding causes significant damage to the foliage, ranging from skeletonization to the consumption of entire leaves. Because the larvae remain hidden within folded leaves tied with silk threads, their presence is often overlooked until substantial leaf area loss has already occurred, making them difficult to target with conventional sprays.

Integrated Pest Management (IPM) strategies for Tethea or are essential for preserving tree health. Management techniques include:

• Regular monitoring of canopy density during the larval stage.
• Applying microbial insecticides like Bacillus thuringiensis for eco-friendly control.
• Using broad-spectrum contact insecticides only if the infestation threshold is exceeded.
• Promoting biodiversity to ensure natural predators, such as parasitic wasps and birds, keep the population in check.