Box Tree Moth

Cydalima perspectalis

1. Identification

• Common name: Box tree moth
• Scientific name: Cydalima perspectalis Walker
• Order: Lepidoptera
• Family: Crambidae

2. Pest description

• Greenish-yellow caterpillars with dark longitudinal lines and a black head, reaching 35–40 mm.
• Adults with white wings and a brown margin, wingspan of 35–45 mm; a less common dark form exists.
• Very voracious caterpillars, feeding exclusively on Buxus spp.
• Invasive species, with a high dispersal capacity and rapid population growth.

3. Main hosts

• Box.
• Other ornamental species of the genus Buxus.

4. Symptoms and damage

• Intense and rapid defoliation, leaving only veins and bare branches.
• Presence of silky webs, dark droppings and caterpillars inside the foliage.
• Drying and death of branches, which can lead to the total decline of the plant.
• Severe aesthetic damage in gardens, parks and ornamental hedges.

5. Biological cycle

• Eggs laid in plaques on the underside of the leaves.
• Caterpillars develop over several weeks, passing through multiple instars.
• Pupation in silky cocoons inside the plant.
• Adults emerge in spring and summer; 3–4 generations per year may occur in mild climates.

6. Monitoring

• Direct observation of caterpillars, webs and droppings on the foliage.
• Pheromone traps for the detection of adults and tracking of flights.
• Regular assessment of hedges and ornamental plants, especially in late spring and summer.
• Early identification of outbreaks to prevent dispersal.

7. Management measures

• Cultural: removal of heavily attacked branches and destruction of infested residues.
• Preventive: frequent inspection of gardens and nurseries; avoid transporting infested plants.
• Biological: application of Bacillus thuringiensis in the young stages of the caterpillars.
• Integrated protection: definition of intervention thresholds, judicious use of authorised insecticides and integration with monitoring and trap data.

Bibliographic references

• CABI – Invasive Species Compendium – Cydalima perspectalis.
• EPPO Global Database – Cydalima perspectalis.
• Alford, D. V. (2007). Pest and Disease Management Handbook. Blackwell Publishing.
• Leuthardt, F. L. G. et al. (2010). Biology and impact of the box tree moth. Mitteilungen der Schweizerischen Entomologischen Gesellschaft, 83, 327–341.
• Wan, H. et al. (2014). Invasion and spread of the box tree moth in Europe. Journal of Applied Entomology, 138, 241–250.