Twin-spot plume moth

Systematic position: Stenoptilia bipunctidactyla belongs to the order Lepidoptera and the family Pterophoridae, commonly known as plume moths. These insects are easily recognized by their slender bodies and deeply cleft wings, which, when at rest, are held horizontally, resembling a T-shape. They are specialized feeders primarily associated with the Lamiaceae plant family.

Host plants: The primary hosts for this species are various members of the mint family (Lamiaceae). This includes economically significant herbs such as sage (Salvia), lavender (Lavandula), and thyme (Thymus). While it thrives in wild habitats, it frequently migrates to cultivated landscapes, causing noticeable damage to both ornamental and medicinal herb gardens.

Biology and life cycle: The life cycle includes egg, larval, pupal, and adult stages. The female moths deposit eggs on the developing buds or foliage of the host plants. Upon hatching, the larvae immediately bore into the buds to feed on the interior tissues. Depending on the climate, the species may complete one or more generations per year, with overwintering occurring in the larval stage hidden within plant debris.

Damage and economic impact: The larvae are the main destructive stage. By feeding inside the floral buds, they prevent the flowers from blooming, leading to bud abortion and stunted growth. The damage is particularly severe because the larvae are protected by the plant tissue, making them difficult to spot and less vulnerable to external environmental factors or non-systemic treatments.

• Conduct visual monitoring of flower buds during late spring and early summer.
• Hand-pick and destroy infested buds to reduce the local population.
• Apply biological insecticides based on Bacillus thuringiensis during the early larval stages.
• Use chemical control with systemic insecticides only when infestation thresholds are exceeded.
• Maintain garden hygiene by removing crop residues and wild Lamiaceae hosts at the end of the season.