Guava Moth (Coscinoptycha improbana)
The guava moth is a pest that is effecting the growing feijoa export market in Northland and has the potential to threaten a large range of commercial crops, as well as your own garden, as it continues to move down the country. Originally from Australia, guava moths were first found in New Zealand in Northland on citrus in 1997. It has become well established in New Zealand. They have been found in Northland, Auckland and Waikato.
WHAT DOES IT LOOK LIKE?
A guava moth is a small, black and white speckled moth with a 15mm wingspan. It is difficult to distinguish from other NZ moths of the same family.
The larvae are pink and up to 8mm long and feed on the ripening fruit.
WHY ARE GUAVA MOTHS A PROBLEM?
Unlike codling moths, Guava moths breed all year round. Guava moths lay eggs in a large range of fruit and nuts throughout the year. Infestation of guava moth larvae cause fruit and nuts to drop prematurely.
PRODUCE AFFECTED BY GUAVA MOTHS
- Feijoas
- Guavas
- Macadamia Nuts
- Citrus
- Loquat
- Plums
- Peaches
- Pears
- Apples
IDENTIFICATION OF THE GUAVA MOTH
Signs to look out for include:
- Premature fruit drop
- Exit holes or small discolorations
- Fruit may appear bruised
- A pin-pricked hole from the larvae
- Brown patches, excreta, and mould inside fruit
If you are noticing these guava moth signs in your garden:
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GUAVA MOTH LIFE CYCLE
The female guava moth lay their eggs onto young fruit. Upon hatching the larvae burrow into the fruit and then spoils it.
The larvae make a tiny pin prick sized hole as it burrows into the fruit. Once inside damage is often difficult to spot until the fully-grown larvae chews its way out.
Spoiled fruits can be contaminated with bacteria, molds and other pathogens that are not visible to the naked eye. Watch out for any foul odors, moldy or mushy spots and signs of discoloration.
Guava moths tend to target citrus fruits over winter, then launches a big infestation on loquat fruit. After the infestation on loquat fruits, it sets the guava moth population up for shifting to summer fruit hosts (stone fruits). Towards autumn, the moth moves on to the feijoa trees.
TIP
Moths pupate in fallen fruit and leaf litter. Keep the area under your trees free of grass, weeds and fallen fruit.
Avoid composting infected fruit as the moths can complete their life cycle in some compost systems.