Reasons Why Worms Get Into Apples and How You Can Prevent It

Reasons Why Worms Get Into Apples blog banner

Have you ever had the experience of biting a juicy and shiny apple, freshly picked up from a tree and got a worm in it? 

Even though worms poking out of apples may be a fun back-to-school theme, it is not a fun idea to picture what is actually happening. 

A whole-grown green worm coming out from an apple! Ew.

Also, do you know that the fictional worm doesn’t look like the actual apple maggot in real life? 

They are not green caterpillars but a white, tapered maggot with stripes on the abdomen.

Since the “worm” is not a traditional earthworm, how do they crawl into apples? 

Keep reading if you want to know why and how, and the ways to prevent it from happening.

How Do Worms Get Inside Apples?

worm is coming out of bitten apple

The answer is quite simple. They don’t! They are born inside the apple! And they don’t look like earthworms.

Here’s how it happens:

  1. During summer, some moths find the apple orchards the ideal place to lay their eggs on.
  2. The moths use a small, sharp tube to slide down the eggs into the apple.
  3. When the larvae are born, it burrows into the fruit creating entry wounds known as “stings.”
  4. The worm turns into a chrysalis and then into moths, which will lay eggs in new fruits.

Why Does This Happen In The First Place?

These wormlike apple maggots (larvae) are the most common apple insect, although they can also be found in pears and English walnuts.

They feel protected in the apple orchards due to shade and humidity. 

It is a safe and comfortable place to lay their eggs, and they know that there will be plenty of food at the time of birth. 

That’s why it is so important to understand the codling moth life cycle to control or prevent infestation.

 Damage Caused by Apple Maggots

  • The first indication of a codling moth infestation is the destruction found inside a ripe apple.
  • Maybe you won’t find the larvae, but you will see the brown mess it left behind.
  • The fruits will become pitted and misshapen and will eventually rot as a result of tunneling through the flesh.
  • If you have an uncontrolled codling moth infestation on your orchards, it can cause substantial damage, often infesting 20 to 90% of the fruit, depending on the variety and location. And it will increase the recovery time needed.

How to Prevent and Control A Codling Moth Infestation?

The key to preventing or controlling a codling moth infestation requires knowledge of its life cycle and habits. 

However, it is difficult to determine the exact time the moth is active since weather plays an important role in when the moth is laying its eggs.

You should start implementing control measures early in the season to act before the adult flies emerge from the ground – which varies each year. 

In many cases, non-chemical approaches control the infestation and limit the damage without the need for pesticides.

However, you will need time and persistence for a long-term and effective codling moth control. 

If the codling moth population has been allowed to build up over a season or two, you should consider that you may be facing a couple of years implementing control measures until you are finally clear.

Step 1 – Understand The Apple Maggots Life Cycle

When adults, the apple maggots live outside the orchard, in brushy areas, and only return to lay eggs. 

Each female fly can lay hundreds of eggs and, after the eggs hatch, the larvae feed for three to four weeks.

When apples are ripe and drop to the ground, the larvae transform into pupae in the soil. 

Pupae spend the winter underground, emerging as adults the following summer.

Step 2 – Sanitation

Sanitation is important to prevent future infestation. 

You should promptly remove debris and fallen fruit – pruning, bins, and props left in the orchard can provide cover for codling moth pupa and harbor larvae, becoming overwintering habitats.

Managing overwintering habitats will help reduce the life cycle of the months for next season.

Step 3 – Place Traps

There are different types of apple maggot traps that you can place in your trees – if you find small flies on the traps, it is time to start controlling them ASAP!

You can buy traps at some garden centers and online or make them yourself. 

Usually, the apple maggot traps are red spheres coated with tanglefoot, a sticky substance that permanently holds insects.

Hang one trap per 100 fruit in each tree to catch the apple maggot flies as they first attempt to lay eggs. Check your traps weekly.

Step 4 – Apply Clay on The Tree

This method is best used combined with traps before any pesticide application. 

You should apply clay to the tree, leaves, and fruits. This will create a visual and physical repellent to insects.

Keep in mind that clay washes off easily, so you will have to reapply after rain and as fruits expand. 

It can protect 90 percent of fruit from apple maggots but requires a lot of effort and consistency.

Step 5 – Use Insecticidal Spray or Pesticides

The use of insecticidal spray is recommended before the female flies lay their eggs or just as eggs are hatching.

Always follow the product label directions and repeat as directed – probably you might need to spray for apple maggots three or four times during the summer.  

Effective pesticides available are esfenvalerate, carbaryl, and spinosad.  

TIP:  Once the larvae have entered the fruit, they are protected from insecticides.

Other Ideas on How to Prevent Worms from Getting into Apples 

  • If you are having trouble controlling an infestation, maybe you can select varieties that are less susceptible to damage, such as early maturing apples.
  • Prune trees facilitate non-chemical management.
  • Check your orchards every week or two and remove any worm-damaged fruit.