Orange Tortrix

Argyrotaenia citrana

1. Identification

• Common name: Orange tortrix
• Scientific name: Argyrotaenia citrana Fernald
• Order: Lepidoptera
• Family: Tortricidae

2. Pest description

• Caterpillars yellowish-green in colour, with a cylindrical body and a brown head.
• Adults with brownish to orange forewings, with irregular patterns; greyish hindwings.
• Defoliating and fruit-boring species, with relevant impact on citrus.
• Caterpillars feed on young leaves, flowers and fruits, rolling leaves with characteristic silk.
• It may have several annual generations in warm climates.

3. Main hosts

• Citrus (orange tree, tangerine tree, lemon tree).
• Avocado tree.
• Apple and pear trees.
• Various ornamental and spontaneous species.

4. Symptoms and damage

• Leaves rolled and bound together by silk threads.
• Holes in young leaves, flowers and fruits.
• Superficial damage to fruits, which may develop into deep lesions.
• Premature fruit drop in severe attacks.
• Reduction in the commercial quality of the fruits.

5. Biological cycle

• Eggs laid in masses on the leaf surface.
• Caterpillars develop inside rolled leaves or on fruits.
• Pupation occurs inside the rolled leaves or in silky shelters.
• Adults emerge throughout the year, with peaks in warm periods.
• Several annual generations, depending on the temperature.

6. Monitoring

• Direct observation of rolled leaves and caterpillars.
• Inspection of young fruits to detect holes.
• Pheromone traps to capture adults.
• Regular sampling in orchards during spring and summer.

7. Management measures

• Cultural: removal of infested leaves and branches; improvement of air circulation in the orchard.
• Preventive: frequent monitoring during higher-risk periods; management of spontaneous host vegetation.
• Biological: application of Bacillus thuringiensis on young caterpillars; promotion of natural parasitoids.
• Integrated Protection: judicious application of authorized insecticides when intervention thresholds are reached; integration of cultural, biological and chemical measures.

Bibliographic references

• EPPO Global Database – Argyrotaenia citrana.
• CABI – Invasive Species Compendium – Argyrotaenia citrana.
• UC IPM (University of California). Orange Tortrix Management Guidelines.
• Hill, D. S. (1987). Agricultural Insect Pests of the Tropics and their Control. Cambridge University Press.