**Olive Moths** (*Prays oleae*) are small moths whose larvae (caterpillars) are a serious, multi-stage pest of olive trees (*Olea europaea*). The conflict is three-pronged, depending on the generation: the first generation larvae damage the **leaves** (minor); the second generation attacks the **flowers** (causing flower drop and yield loss); and the third, most destructive generation attacks the **fruit**, boring into the olive and causing premature drop and rendering the fruit useless, leading to **major economic loss**.
Taxonomy and Classification
Olive Moths belong to the order Lepidoptera. They undergo complete metamorphosis. The moths are synchronized to the olive tree’s phenology, with three distinct, overlapping generations that target three different parts of the tree (leaves, flowers, fruit) during the growing season.
Physical Description
Adult Moths are minute, <1/2 inch wingspan.
- **Adult Moth (Key ID):** Small, silvery-gray moth with black, mottled markings. They are nocturnal and inconspicuous.
- **Larva (Key ID):** Small, greenish-yellow to pinkish caterpillar.
- **Damage Sign (Key ID):**
- **Leaf Damage:** Mining trails within the leaf tissue, especially overwintering damage.
- **Flower Drop:** Heavy loss of olive flowers (blossom drop) in spring.
- **Fruit Drop:** Small, young olives drop prematurely, often with a visible tunnel or entry hole near the stem end.
- **Conflict:** Consistent, cumulative loss of olive yield throughout the season.
Distribution and Habitat
Olive Moths are native to the Mediterranean region and are found anywhere commercial olives are grown. Their habitat is the leaves, flowers, and fruit of the olive tree, which serve as sequential food sources for the three generations.
Behavior and Conflict
The conflict is the complexity of controlling multiple life stages simultaneously.
- **Flower Generation:** The generation that feeds on the flowers (May-June) is often the most critical, as a high population can destroy the entire year’s crop potential.
- **Hidden Feeding:** Much of the larval feeding occurs inside the plant tissue (leaf mine, flower bud, fruit pulp), protecting the larvae from contact sprays.
- **Year-Round Pressure:** The moth’s continuous life cycle means the olive tree is under pest pressure throughout all stages of development.
Management and Prevention
Control is integrated pest management (IPM), with precise timing of interventions.
- Use pheromone traps to track the flight peaks of the three generations, allowing growers to target sprays only during the flight/egg-laying periods, minimizing impact on beneficial insects.
- Introduce or protect native parasitic wasps (*Ageniaspis* species) which are highly effective at controlling the moth larvae.
- Targeted applications of *Bacillus thuringiensis* (Bt) during the peak flower generation is common, as Bt is non-toxic to beneficial insects.
- Treatments are typically avoided during the fruit generation unless populations are extremely high, as residue on the fruit is undesirable.
Conservation and Research
Olive Moths are managed as high-priority pests in olive cultivation. Research focuses on optimizing pheromone lures for mass-trapping, improving the synchronization of chemical application with the vulnerable flower stage, and developing host plant resistance.