Lepidoptera : Tortricidae : Cydia pomonella

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Codling Moth, Cydia pomonella, has been a fruit pest for a long time. Of Eurasian origin, it was introduced into Tasmania in the 1850’s and has since spread to all Apple growing areas of Australia. Codling Moth is a cosmopolitan insect that occurs in most countries where pome fruits are grown.

Holes in Apples and Pears plugged with Codling Moth larvae droppings (frass) is the outward sign of attack by Codling Moth. The situation inside the fruit is much worse, as larvae chew their way into the fruit core, where they may feed for several weeks. Codling Moth is a serious pest – their larvae can destroy an entire fruit crop if not controlled.

Best Treatment for Codling Moth

Codling Moth is a Caterpillar pest that is difficult to control. There is no quick fix, and none of the prevention and control methods described here should be relied on solely. A combination of methods is much more effective.

You could try Yates Success Ultra Insect Control or Yates Nature’s Way Caterpillar Killer Dipel, which are both registered against Codling Moth in home gardens. Spray when caterpillars or their damage first appears. It is important to spray both sides of all foliage. Repeat spray (at the intervals as recommended on the product label) to help control any newly hatched caterpillars.

You need to act quickly because once Codling Moth larvae bore into fruit, the sprays will not be effective.

Garden hygiene is very important in the management of Codling Moth. Any infested fruit that has fallen or is still on the tree, should be destroyed to break the life cycle of this pest.

Trapping is another important component of Codling Moth control. Commercial pheromone traps and home-made lure traps can significantly reduce the number of egg-laying moths fluttering around your trees. Cardboard bands around tree trunks can trap cocooning larvae for you to squash.

Exclusion bags around your fruit will prevent female Codling Moths laying eggs on the fruit. This method is only practical if you just have a few trees to protect.

One of your best weapons against a pest is knowledge about that pest - such as what we outline in the following sections.

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What are Codling Moths, &
How to Get Rid of Them

Codling Moth is believed to originate from Europe, and western and central Asia. Over the last couple of centuries it has spread to most areas of the world where pome fruit is grown. Its spread around the world has mostly been through the movement of infested fruit. It is a pest of quarantine concern in several countries and regions where it currently does not occur (e.g., Colombia, Japan, South Korea, and Taiwan).

Codling Moth is one of the most serious fruit pests that occurs in Australia and it is established in all Australian states, except Western Australia and the Northern Territory. Codling Moth is a declared pest in Western Australia, but occasional outbreaks do occur in that state. Any suspect infestations should be reported to the Western Australian Pest and Disease Information Service (PaDIS). Early detection and reporting of Codling Moth will help protect the Western Australian pome fruit industry.


Description

Adult

Codling Moth adults are a nondescript greyish brown colour, except for an iridescent bronze patch near the tip of each forewing. They are about 10 mm to 12 mm long, and they have a wingspan of about 18 mm. Codling Moths rest with their wings folded in a roof or tent shape over their bodies.

Eggs

Codling Moth eggs are pale, semi transparent, flattened, oval eggs about 1 mm long.

Larvae

A newly hatched Codling Moth larva is white with a black head and is only a millimetre or two long. Mature Codling Moth larvae are distinctly pinkish in colour with a brownish head, and they grow to about 18 mm long.

Pupae

Codling Moth pupae are dark brown and shiny, and are covered by a tough, silken cocoon.

Life Cycle

Like all moths, the Codling Moth develops through a life cycle of complete metamorphosis – egg to larva to pupa to adult moth. Codling Moth has a different number of generations per year, depending where it is breeding in Australia. Cooler parts of Australia have one or two generations per year, but warmer districts may have a partial 3rd generation. The different generations may overlap considerably throughout the growing season.

Eggs are usually laid singly on fruits, or on leaves and stems near developing fruits, around dusk. Hatching larvae initially feed on leaves and then burrow into fruit, where they go through five growth stages (instars) inside. Mature larvae chew an exit hole and crawl out at night to spin a cocoon under bark, in crevices on the tree or in dry ground under the tree.

Most of the cocooned larvae form a pupa, from which adult moths emerge about two weeks later around mid-summer to begin the 2nd generation. A small percentage of the cocooned larvae hibernate (technically known as diapause) until the following spring.  Eggs laid during summer from the 2nd generation develop through to fully grown larvae and they too mostly enter diapause until the following spring. As day-length during spring increases, those hibernating larvae pupate and then moths begin emerging a couple of weeks later. In some areas, some of the 2nd generation hibernating larvae may develop completely, and a 3rd generation of moths emerge to attack late fruit varieties.

What Plants are Impacted by Codling Moths

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Symptoms of Codling Moths

  • Chewed leaves, especially early in the season when fruit is forming.
  • Holes in fruit plugged with larval droppings (frass) is a classic sign of codling moth attack.

How to Prevent Codling Moths Appearing

Monitor

  • Inspect trees regularly during fruiting season. Look for damaged leaves and frass packed holes in fruit.
  • Try a homemade lure pot (a suspended jar containing a four parts water to one part port wine, or perhaps fermenting apple juice) to trap moths over spring and summer. Codling Moths are attracted to the smell of the fermenting fluid. This may not necessarily completely prevent an infestation of Codling Moth larvae, but at least the traps will alert you to the presence of egg-laying moths.

Prevent

  • Deploy commercially available Codling Moth pheromone traps. These traps catch male moths and prevent them mating with and fertilising female moths. Follow label instructions.
  • Use commercially available exclusion bags to prevent female moths reaching fruit and laying eggs on them.
  • Garden hygiene is an important component of Codling Moth control. All infested fruit – on the ground or on the trees should be destroyed.
  • Brush loose bark from the branches and forks of trees where Codling Moth larvae might pupate.
  • Tape bands of corrugated cardboard (from about December onwards) around trunks and limbs of trees for Codling Moth larvae to spin cocoons or pupate under. Inspect cardboard regularly and squash any cocoons and pupae found. Or you could simple install a new band of cardboard and burn the infested one.
  • A band of glue, or grease, or sticky tape on the trunk may trap moths which have emerged from pupae underground and flutter up the trunk of the tree. It is important to note that this method will have no effect on any moths emerging from pupae under bark further up the tree.
  • Yates Success Ultra Insect Control, which contains Spinetoram, is registered against Codling Moth on pome fruits. Yates Nature’s Way Caterpillar Killer Dipel, a bio-insecticide, is also registered for use in home gardens. You need to act early because the spray won’t be effective once Codling Moth larvae have entered the fruit. Applications should be made at 7 to 14 day intervals during periods when eggs are hatching. Follow label directions.

Natural Enemies

  • Tiny parasitic Trichogramma wasps parasitise Codling Moth eggs.
  • An introduced parasitic wasp, Mastrus ridens, which attacks hibernating Codling Moth larvae in their cocoons, has been released in various parts of Australia. It may be some years before there are enough wasps to have any influence over Codling Moth populations.

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