Apple Maggot

Rhagoletis pomonella

Also known as Railroad Worm

Apple maggot trap

Apple maggot fly [Credit: Elena Dadale Jones]

Host Plants:

In the garden: Hawthorn
On Crops: Apple

Where Found:

Much of North America

Description:

Small black flies with even tinier white markings emerge in early summer and lay their eggs just under the skin of immature apples. The fly larvae tunnel through the fruit as they feed, making the fruit lumpy, disfigured, and prone to rot.

Damage:

Meandering tunnels in apples, just beneath the skin and extending to the core, are usually the work of apple maggots. Small, rice-like maggots may be present, especially in apples that have dropped to the ground. The larvae move from fallen fruit to the soil to pupate. Adult flies overwinter as pupae about 2 inches (5cm) deep in the soil.

Preventing Problems:

In areas where this pest is common, hang pheromone-baited sticky traps in apple trees in early summer, before fruits grow larger than your thumbnail. Newly emerged flies will be attracted to the traps rather than each other, but it is important that the traps be in place before the flies mate and lay eggs. A single female apple maggot fly can lay 300 eggs in her short, 30-day lifespan. Promptly pick up fallen apples and chop them into pieces before composting them.

Managing Outbreaks:

Enclosing perfect green apples in clear plastic sandwich bags will protect them from apple maggots and other pests. Some apple varieties are more susceptible to apple maggot damage than others.

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