Ash moth

Abraxas pantaria

1. Identification

• Common name: Ash moth
• Scientific name: Abraxas pantaria L.
• Order: Lepidoptera
• Family: Geometridae

2. Pest description

• Light-coloured caterpillars, with dark spots distributed along the body, reaching 25–30 mm.
• Adults with white wings speckled with brown and black spots; wingspan of 30–40 mm.
• Defoliating species, with caterpillars that feed mainly on young leaves.
• Most intense activity in spring and early summer.

3. Main hosts

• Ash.
• Other spontaneous broadleaves may occasionally serve as a secondary host.

4. Symptoms and damage

• Perforations and irregular cuts in the leaves.
• Partial defoliation in cases of high population density.
• Reduction of tree vigour, especially in young specimens.
• Damage generally localised, but which can be significant in years of greater abundance.

5. Biological cycle

• Eggs laid on the underside of the leaves in late spring.
• Caterpillars develop over several weeks, feeding actively on the leaves.
• Pupation occurs in inconspicuous cocoons on the vegetation or in the soil.
• Adults emerge in summer; generally one generation per year.

6. Monitoring

• Direct observation of caterpillars and leaf damage in spring.
• Assessment of the intensity of defoliation in young trees.
• Search for pupae or cocoons in the surrounding vegetation.
• Monitoring of outbreaks in urban and forest areas with the presence of ash.

7. Management measures

• Cultural: removal of heavily attacked branches and destruction of infested residues.
• Preventive: regular monitoring of ash stands, especially in spring.
• Biological: promotion of natural enemies and 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 data.

Bibliographic references

• CABI – Invasive Species Compendium – Abraxas pantaria.
• EPPO Global Database – Abraxas pantaria.
• Carter, D. J. (1984). Pest Lepidoptera of Europe. Dr W. Junk Publishers.
• Alford, D. V. (2007). Pest and Disease Management Handbook. Blackwell Publishing.
• Hausmann, A. et al. (2001). Geometrid moths of Europe. Apollo Books, 2, 1–300.