Limacodid moth

Systematic position: The limacodid moth (Latin Apoda limacodes) belongs to the order Lepidoptera and the family Limacodidae, commonly known as slug moths. The common name refers to the peculiar appearance of the larvae, which lack visible legs and move in a slug-like manner, making them distinct from other common caterpillars.

Host plants: This pest is a polyphagous insect that primarily attacks deciduous trees. In an agricultural and horticultural context, it is frequently found on oak, beech, and lime trees, but it also causes significant damage to orchard trees such as apples, pears, and plums, often residing on the undersides of the leaves.

Biology and life cycle: The species typically completes one generation per year. Adult moths are active in early to mid-summer. Females deposit eggs on the host leaves. Upon hatching, the larvae feed throughout the summer, and by autumn, they construct a hard, spherical or barrel-shaped cocoon, where they overwinter until the following spring pupation.

Nature of damage: Larval feeding can be quite devastating during high-population years. Early instars perform skeletonization of the leaf tissue, while later stages consume entire sections of the leaf blade, often leaving only the primary veins intact. Heavy infestations can lead to premature leaf drop and overall vigor loss of the tree.

Protection measures: Management depends on the level of infestation and the value of the host plants. Practical control steps include:

• Monitoring tree canopies for signs of larval feeding during summer.
• Physical removal of larvae or cocoons in small garden settings.
• Applying biological insecticides containing Bacillus thuringiensis during the early larval stage.
• Using broad-spectrum contact insecticides only if the pest population exceeds economic thresholds.