Plant Doctor Archive

 I’VE got a great crop of apples this year, but lots of them have been attacked by codling moth. What should I do to prevent it happening again next year?

  CODLING moth are a pain — there’s nothing worse than biting into a nice looking apple to find a codling moth caterpillar has beaten you to it, leaving its dirty brown tunnel leading into the centre of the fruit. Corrugated cardboard strips wrapped fully around main branches (with the corrugations facing inwards) can sometimes convince mature larvae that this is a good place to shelter over winter. Check the cardboard every couple of weeks and destroy any cocoons.

You can also use grease bands around trunks and branches during spring to trap emerging adults as they crawl up the tree. Make them from strips of old material covered in grease or petroleum jelly. Or buy a pheromone trap, available from garden centres, to trap the male moths and prevent mating. Hang them in the trees during late spring and summer.

For really good control, however, you often have to resort to spraying with products like Fruit Tree Spray or Carbaryl, starting around late November, before caterpillars tunnel into the fruit, and continuing until just before harvest. Follow the label directions carefully, particularly with regard to withholding periods before eating fruit.

Weekend Gardener, Issue 145, 2004, Page 26

• The views expressed here are not necessarily those of the RNZIH
• Content or advice may be out-of-date.