Four ways to manage codling moth naturally

Codling caterpillars eat through leaves. Picture: Shutterstock.
Codling caterpillars eat through leaves. Picture: Shutterstock.

There were tears the first time codling moth (laspeyresia (cydia) pomonella) got into our apple trees.

Unfortunately even if your trees are healthy, if there's any codling moth in the immediate neighbourhood it's only a matter of time before they find their way there.

An adult codling moth. Picture: Shutterstock.

An adult codling moth. Picture: Shutterstock.

But there are methods to managing coddling moths. Here's what I do to help protect our trees.

But first, understanding their lifecycle will help manage them.

First, tiny eggs are laid on leaves after dusk, this starts to happen once night time temperatures reach 15 degrees or higher.

Eggs hatch after around 10 days, they feed on leaves then eventually move into fruit where they'll chew their way into the core and eat for three to five weeks.

Once they're full, they leave the fruit and move down the trunk, looking for a loose crevice to make a cocoon.

Codling moth lava feeding on the fruit core of an apple. Picture: Shutterstock

Codling moth lava feeding on the fruit core of an apple. Picture: Shutterstock

This is usually under loose bark or in the ground directly near the base of the trunk.

It'll then metamorphose into an adult moth which then flies at night to mate and repeat the cycle.

In cooler areas the moth will have two productive cycles each season, while in warmer areas it will have three.

So you have to manage the moth throughout the whole season to catch these cycles.

The one thing everyone I ask agrees on is that you have to do more than one method if you want success.

Disrupt the caterpillar's cocoon cycle with the truck trap. Picture: Hannah Moloney.

Disrupt the caterpillar's cocoon cycle with the truck trap. Picture: Hannah Moloney.

Trunk trap

Wrap hessian cloth or corrugated cardboard around the base of the trunk to trap any caterpillars looking for a place to pupate.

Inspect every three weeks to see if there are any cocooned caterpillars and destroy them. Then replace with a new collar.

Pheromone trap

There are a range of pheromone traps you can use for catching codling moth.

What is a pheromone? It's a secreted or excreted chemical factor that triggers a social response in members of the same species, in this case it mimics a "mating smell" (not the technical term) and attracts the codling moth directly to it.

The pheromone trap lures codling moths onto a sticky glue trap. Picture: Hannah Moloney.

The pheromone trap lures codling moths onto a sticky glue trap. Picture: Hannah Moloney.

How does this kind of trap work?

The codling moth is attracted by the manufactured pheromone lure, it enters the trap and is caught on the non-drying glue inside the trap. The glue insert can later be removed for inspection and replacement.

The only challenging thing with the pheromone trap is the price.

These kits range from $30 to $50, so not an option for everyone, and honestly our trees are too young to even produce that amount of fruit. I just panic-bought it when I didn't think there was another options.

But then I looked into some DIY methods which, while quite different to the above (not pheromone based), can still trap codling moth. Like this one from Utah State University Extension where you mix water, molasses and yeast together in a bucket.

Apparently the codling moth is attracted to the smell, dives in, gets stuck, dies and your apples live happily ever after.

More lifestyle:

Beneficial plants and insects

It's a good idea to include strategic plants in your orchard which attract beneficial insects that eat codling moth.

These plants include clover, Queen Anne's lace, dill and fennel.

These beneficial insects I'm referring to are the Trichogramma - a minute wasp, less than half a millimetre long. The adult female lays her eggs into the codling moth eggs.

There are also a number of other wasps, night flying birds, tree frogs and small bats that can eat codling moth.

So the more diverse plants you have, the better. Check out edible forest gardens to learn more.

Horticultural glues

People also use a type of "horticultural glue" at the base of the trunk to prevent some of the female moths from crawling or fluttering up the tree trunk.

It'll also stop ants and other crawling insects you don't want in your trees.

Put masking tape on the trunk first, then apply a very thin layer of the glue on top of that (with anything but your fingers - it's real sticky).

The glue trap on the tree truck stops caterpillars climbing into the trees from the ground. Picture: Hannah Moloney.

The glue trap on the tree truck stops caterpillars climbing into the trees from the ground. Picture: Hannah Moloney.

The codling moth get stuck on there as they try to walk up the trunk. You need to replace it every two to three months.

Importantly, you can't use vaseline. Vaseline popped up again and again as an alternative to commercial glues - so I tried it.

But it doesn't last more than a few days, at which point codling moths, caterpillars, ants etc will happily crawl over it. So don't waste your time there.

I bought a 500-gram tub of natural horticultural glue from nursery for around $13 - the tub will last for years and it will work.

Also, check the laws around glue traps for insect capture in your state.

In Victoria glue traps require a barrier or fence around the traps to prevent animals coming into contact with them. This is in the spirit of animal welfare.

You can read more about it at agriculture.vic.gov.au

Other things to note

Never leave fruit on the ground - it'll rot and provide food for the codling moth. Keep your orchard clean.

If possible, run your poultry through the orchard, they'll eat any rotting fruit and any codling moth that happens to be in the top layers of the soil.

Sheet mulching around your trees can also help slow codling moth coming out of the ground as it creates one extra barrier it has to break through.

  • Hannah Moloney and Anton Vikstrom are the founders of Good Life Permaculture, a landscape design and education enterprise regenerating land and lifestyles.