Fruit Borer

Symptoms by part

Causes

• Adult moths laying eggs on the surface of young, developing fruit.
• Warm temperatures that speed up the life cycle of the larvae.
• Lack of physical barriers to prevent egg laying on the fruit skin.

Could be confused with

• Fruit rot diseases · Fungal rots usually present with fuzzy or discolored surface growth without the distinct entry holes and internal tunneling caused by larvae.
• Bird damage · Birds create large, jagged, open wounds on the exterior of the fruit rather than the small, precise entry holes left by boring larvae.

Treatment

1. 1. Hand pick and destroy any fruit showing signs of entry holes to stop the larvae from completing their life cycle.
2. 2. Bag individual fruits with fine mesh or paper bags as soon as they reach a small size to physically block moths from laying eggs.
3. 3. Apply Bacillus thuringiensis to the fruit surface during the early stages of fruit development to target young larvae before they bore inside, follow the label.

Without chemicals

• Bagging individual fruits with fine mesh or paper bags.
• Removing and destroying all fallen fruit from the ground daily to prevent larvae from pupating in the soil.
• Pruning branches to improve airflow and reduce the humidity levels that favor moth activity.

Chemical options

• Bacillus thuringiensis, spray onto the fruit surface during early development to target larvae, follow the label.

Preventing it

• Clean up all fallen fruit from the orchard floor immediately to break the life cycle.
• Use pheromone traps to disrupt mating cycles if the infestation is recurring.
• Encourage natural predators like parasitic wasps by planting diverse flowering plants nearby.

When to act

Act as soon as you see the first entry holes on young fruit. If the infestation is widespread and affecting the majority of your harvest, remove the affected fruit immediately to protect the remaining crop.

Questions people ask

Can I eat fruit that has been attacked by a fruit borer?

It is generally best to discard affected fruit because the tunneling larvae introduce bacteria and fungi that cause the fruit to rot from the inside out.

Why does the fruit fall off the tree before it is ripe?

The larvae damage the internal structure of the fruit, which triggers the tree to abort the fruit as a defense mechanism or because the fruit can no longer sustain itself.

Plants it affects

• Durian
• Longan