Pine cone caterpillar

Dioryctria mendacella

1. Identification

• Common name: Pine cone moth
• Scientific name: Dioryctria mendacella Staudinger
• Order: Lepidoptera
• Family: Pyralidae

2. Pest description

• Adults: Moths with a 22–28 mm wingspan, greyish-brown forewings with lighter irregular patterns; whitish hindwings.
• Larvae: Reddish-brown to brownish caterpillars, with a dark head; they develop inside the cones, young shoots and buds.
• Pupae: Formed inside the cones or in resinous shelters.
• Eggs: Laid singly or in small groups at the base of the cone scales or on young buds.

3. Main hosts

• Pines, especially Pinus pinea, P. pinaster, P. halepensis and other Mediterranean species.
• Preference for young cones and reproductive tissues.

4. Symptoms and damage

• Borings and galleries in the cones, with resin exudation.
• Cones destroyed internally, with premature drop.
• Significant reduction in pine nut production under repeated attacks.
• Damage to young buds and shoots, which can affect growth.
• Presence of frass and hardened resin in the attacked areas.

5. Biological cycle

• One generation per year, with possible regional variations.
• Adults active in summer; egg-laying on young cones.
• Larvae develop inside the cones over several months.
• Pupation inside the cones or in resinous chambers.
• Development favoured by hot summers and high availability of young cones.

6. Monitoring

• Observation of cones with resin exudation and frass.
• Opening of suspect cones to detect larvae and galleries.
• Monitoring of young buds in stands with a history of the pest.
• Light traps can help in detecting adults.

7. Management measures

• Cultural: Removal and destruction of infested cones; reduction of local foci; appropriate density management to promote tree vigour; avoid water stress.
• Biological: Use of authorised entomopathogenic microorganisms; application of microbial bioinsecticides; conservation of natural enemies through appropriate cultural practices.
• Integrated protection: Regular monitoring; intervention only when necessary; practices that reduce the survival of larvae inside the cones and the availability of susceptible reproductive material.

Bibliographic references

• EPPO Global Database – Dioryctria mendacella.
• CABI Invasive Species Compendium – Dioryctria mendacella.
• Roques, A. (1999). Insects and Diseases of Mediterranean Forest Systems.
• Mutuura, A. & Munroe, E. (1972). Taxonomy and distribution of the genus Dioryctria. Memoirs of the Entomological Society of Canada.
• Cadahia, D. (1980). Plagas de los pinares españoles. ICONA, Madrid.