The olive fruit fly (also known as olive fruit fly or olive fruit fly), scientific name Bactrocera oleae , is a parasitic insect that attacks olive trees and causes significant damage to the olives, compromising the quality of the oil produced.
It is called this way because it loves to lay its eggs inside the drupe (the olive itself).
How does the olive fly form?
The eggs laid in the olives hatch into tiny worms that quickly transform into ravenous tenants. These larvae, veritable moles inside the fruit, feed on the pulp, creating tunnels that compromise its quality.
- The olives become the cradle: the olive fly lays its eggs there.
- The little saboteurs hatch: from the eggs the larvae hatch, ready to devour the fruit.
- A feast inside: the larvae gorge themselves on the pulp, creating tunnels that damage the olive.
How does the olive fly work?
Not only are they insatiable eaters, olive fruit fly larvae also prove to be skilled saboteurs. Like infected moles, they burrow inside the fruit, digging tunnels that compromise its pulp and health.
The consequences of their actions are evident:
- Inexorable rot: The galleries dug by the larvae encourage the entry of mold and bacteria, causing inexorable rot that ruins the fruit.
- Premature drop: Weakened and rotten olives cannot support the weight of the tree, falling to the ground before they ripen.
In a nutshell:
- Treacherous Tunnels: The larvae dig tunnels inside the olives.
- Inevitable rot: The holes created favor the proliferation of pathogens.
- Compromised fruit: Rotten and weakened olives fall prematurely.
How to recognize the olive fly?
To effectively combat the olive fruit fly, it's essential to know how to recognize it. Here are some key details to help you identify it:
The adult:
- Size and color: A small insect (about 4-5 mm) with a yellowish to light brown body, characterized by black spots on the back.
- Head: Yellow, with clearly visible eyes.
- Wings: Transparent, with a dark spot at the tip.
- Behavior: Females lay eggs inside the olives, preferably when the stone is hardening.
The larvae:
- Color: Whitish, almost translucent.
- Size: Small, about 3-4mm long.
- Shape: Worm-shaped, with a cylindrical and slightly pointed body.
- Where to find them: Inside infected olives, where they feed on the pulp, causing rot and premature fruit drop.
Signs of infestation:
- Tiny Holes: Female olive fruit flies create tiny holes in the surface of olives to lay their eggs.
- Rot: The larvae, feeding on the pulp, cause rot and blackening of the fruit.
- Premature drop: Infested olives often drop prematurely from the tree.
Recognizing the olive fruit fly and its symptoms is the first step to effective and timely control. Regularly monitoring olive groves and intervening with appropriate methods, depending on the severity of the infestation, is essential to safeguarding the harvest and plant health .
It is important to consult an expert agronomist or an agricultural technical assistance service who can help you choose the control method best suited to your needs and your olive grove.
The life cycle of the olive fruit fly varies from a few weeks to a few months, depending on climatic conditions. In warmer areas, several generations can complete a year, while in cooler climates the cycle is longer.
- Egg stage: The female lays eggs inside the olives, especially during the stone hardening stage. The eggs hatch after a few days.
- Larval stage: The small, whitish larvae feed on the fruit pulp, creating tunnels that compromise its quality and encourage the entry of pathogens.
- Pupal stage: Once their development is complete, the larvae pupate in the soil.
- Adult stage: After emerging, adults emerge from the ground and mate, starting a new cycle.
Where is the olive fly found?
As its name suggests, the olive fruit fly prefers areas where olive trees are present. It is an insect closely tied to this crop, so much so that it cannot survive without it.
- Distribution: The olive fruit fly is widespread throughout the olive-growing areas of the Mediterranean, preferring warm, dry climates.
- Presence in Italy: In Italy, it is particularly widespread in the southern and island regions, where the climate favors a greater number of generations per year.
How to recognize the olive fly
Recognizing the olive fruit fly and its habitat is the first step to effective control. Paying attention to signs of infestation, such as holes in the olives, rot, and premature fruit drop, is essential for timely intervention.
The integration of different control strategies, including preventive, biological, cultural, and, if necessary, chemical methods, is the key to effective and sustainable control of the olive fruit fly.
Only with a careful and informed approach will it be possible to protect the olive groves and guarantee a healthy, high-quality harvest.
Are there olives that are immune to the olive fly?
The Simone cultivar (from which we produce a single-variety oil that received Gambero Rosso recognition with two leaves in 2024) has a particularity: the drupe (olive) has an aromatic pool that is not appreciated by the olive fly, therefore it is naturally (without chemical treatments) free from it: the result is an oil that will certainly not have defects related to the bite of the olive fly.
Generally speaking, clearly, if an olive affected by a fly is crushed, it will produce a defective oil.
