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Dealing with Codling Moth
Codling moth are the bane of professional and backyard apple growers everywhere. The grubs tunnel their way into the centre of the apple, eat out the core then tunnel out again leaving a brown rotting mess in their wake. They are also partial to pears and quince and will attack crab apples. As populations build year on year it is one of the few pests I recommend controlling so what exactly can you do to slow down this damage?
Know thy enemy – The life cycle of Codling moth
- Moths emerge when you see flowers in full bloom
- They lay eggs when temperatures are 15C or higher
- Eggs hatch in around 10 days
- Small caterpillars feed on leaves before moving onto fruit where they stay for 3-5 weeks
- They then move to the trunk, soil or other suitable location nearby to cocoon
- These cocoons will then hatch and start the cycle over
- We can get 2-3 generations in one year which can result in rapid population explosions
Up until recently the only products that had any effect on codling moth were pretty dangerous to use and have subsequently been taken off the market. But in the last year a new product called Success Ultra has been registered for codling moth and for all reports it seems to be working really well and is very safe to use. As with all chemicals do not spray when very hot or when your trees are suffering from drought stress. Pick a still day where no rain is expected for at least 6 hours. Obey all withholding periods making sure you don’t eat the fruit within this time.
The non chemical solution
All of the following controls are helpful but none on it’s own is likely to rid you of codling moth so I recommend trying a combination of the following options. Remember you will be dealing with last years population as well as those in your neighbourhood so expect a slow decline rather than an immediate fix. Also remember crab apples are apples too and will harbour codling moth populations so remove all fruit or treat the same as a fruiting apple. The same applies to pears and quince.
All year round A band of hessian or even cardboard can be tied loosely around the trunks of trees. When the grubs have emerged from the apples they will seek a hiding place on or near the trunk. The band will provide this and if taken off and destroyed then replaced every two months the next years’ population will be reduced markedly. Don’t forget to take this off otherwise you make the problem worse having provide perfect living conditions for the grubs – the idea is to trap and destroy.
Late Winter – Spring
To attract and trap the moths hang a jar or can in the tree with a small mixture of water and sugar or honey (enough to cover the bottom of the jar). Replace the mixture every week to 2 weeks if possible. This will not reduce numbers drastically but will give you an indication of when the moths are active and when spraying will be most effective. You can also purchase Pheremone lures for similar results.
Spring (or around 15C+)
To smother any eggs and prevent them from hatching spray one part white oil fifty parts water at weekly intervals for a month. Ideally then continue this regime throughout the warmer months to interrupt the hatching cycle
When fruit appears Inspect your fruit regularly and destroy and infested apples. Pick up any fallen fruit and destroy. You can either submerge them in water or seal them in a black plastic bag and cook them in the sun. Do not compost the fruit until you know the grubs are dead!
Exclusion bags can be used to keep out the grubs – remove a week before harvest to develop colour.
Also worth trying Plant dill, coriander, alyssum, cosmos to attract predatory wasps and other helpful bugs
Chooks foraging under apple trees will clean up fallen fruit and cocoons
Most importantly remember the adult is a moth capable of flying from yard to yard so controlling your population will reduce damage not eradicate the problem. Keep this in mind and check your fruit for nasty surprises.
Have you tried something that worked for you? Let us know in the comments section and we will spread the word. And good luck!