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Environment

Guava moth

Guava moth

Coscinoptycho improbana

What does it look like?

It is a small, black and white speckled, inconspicuous moth with a 15mm wingspan. The moth lays its eggs on the fruit surface, and the caterpillar burrows in the fruit. The caterpillar is pinkish and grows to 5-7mm in length.

 

Adult guava moth with larva (inset) (Photo credit: HortResearch).

Why is it a problem?

It lays eggs in a large range of fruit and nuts throughout the year, including citrus, loquat, plums, peaches, pears, apples, macadamia, feijoa and guava. From the outside fruit has circular brown patches and excreta (frass) extrudes from infested fruit and nuts. Feeding by the caterpillar leaves rotting, brown patches, excreta and mould inside the fruit, making the fruit inedible and causing early fruit drop before fruit is fully ripe.

What can I do?

Physical control - Cover green fruit you wish to protect with fine mesh cloth such as curtain netting to prevent moths laying eggs on fruit. Secure with tape to the supporting branch.

Remove fallen and rotting fruit and associated leaf litter from beneath trees and bury or burn it. This will destroy pupating guava moths.

  • Mating disruption (commercial orchards only) - Attach Asian peach fruit moth pheromone dispenser twist ties to tree branches at 800 dispensers/ha – even coverage of the area is essential – twist ties dispense pheromone for 14 months.
  • Asian peach moth pheromone dispensers can be sourced from Etec Pukekohe imported from Japan.

 

Loquats bagged to protect from guava moth (Photo credit: Jenny Dymock)Loquats bagged with a fine mesh cloth protect the fruit from guava moth (Photo credit: Jenny Dymock).

 

Management table

Physical control

  • Wrap green fruit with fine mesh cloth such as curtain netting to prevent moths from laying eggs on ripening fruit.
  • Secure mesh to supporting branch with tape.
  • Allow enough room for fruit to swell as it ripens
  • Remove fallen and rotting fruit and associated leaf litter from beneath fruit trees. Bury or burn debris collected to destroy pupating guava moths

Mating disruption

(commercial orchards only)

  • Attach Asian peach fruit moth pheromone dispenser twist ties to tree branches at 800 dispensers/ha – even coverage of the area is essential – twist ties dispense pheromone for 14 months.
  • Asian peach fruit moth female pheromone produced by the dispensers confuses male guava moths which use up their limited energy reserves unsuccessfully searching for "phantom" females while guava moth females remain sterile.
  • Asian peach moth pheromone dispensers can be sourced from Etec Pukekohe imported from Japan.

Trapping

  • Guava moth pheromone delta traps with sticky bases available from garden centres and rural suppliers.
  • Traps are used for monitoring guava moth only – do not reduce infestation of fruit.

Chemical control

  • No insecticides registered for use against guava moth.
  • Wide range of fruit crops affected by guava moth means no single product or product group can be recommended for insecticide control.
  • Insecticides used for codling moth may be useful but existing specifications for their safe use do not cover all the fruit and nut crops that guava moth infests.

Please read the label health and safety guidelines for chemical use

More information

For further information or control advice please contact one of our Biosecurity Officers at the Northland Regional Council on 0800 002 004