First found on our shores in Northland in 1997, the Guava Moth has been slowly making its way south, and sadly it’s recently arrived in Auckland.
Like Codling Moth, Guava Moth lay their eggs onto young fruit. Upon hatching the larvae burrow into the fruit and then spoils it. But unlike Codling Moth, Guava Moth breed all year and can infest a large range of fruit, including: Feijoa, Guava, Citrus, Peaches, Plums, and even Chillies.
But thankfully all is not lost. There is still a lot to learn, but there are definitely treatment options that will help.
Though as it’s early days we’d love to hear feedback on your experiences with them, as this may help us improve our advice.
Guava Moth: A Brief Guide
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.
How to spot it?
Check for immature fruit drop
Fruit often drops early.
Check windfall fruit regularly for markings such as exit holes or small discolouration.
Fruit often appears bruised.
In the later stages some larvae excrement may be visible.
Control Measures
Sadly there are no easy solutions to this problem, Below are a few control measures that will help deal with the problem. For best results, especially when dealing with severe infestations using multiple methods will provide the best results.
Note: Due to their continuous lifecycle, once they are spotted it’s worth controlling their numbers to stop the problem getting out of control.
Once discovered don’t ignore the problem, as it will soon get worse. If possible coordinate with your neighbours for best results.
Pheromone Traps
Works by replicating the pheromones produced by the female moth to catch the male moths.
Works best to help control low level infestations or to help monitor the problem.
Assemble traps as per instructions on the packet and hang in a tree around 1.5m above the ground.
Little Bugga Moth Trap
The trap works by attracting moths to the trap with a solar light. Oil or a sticky trap card then catches the moths.
These traps aren’t targeted and will trap a wide array of different moths. Using a sticky trap will allow you to identify the moths. A pheromone trap lure can also be used to further increase the effectiveness of these traps.
Neem Oil
Use pheromone traps to find out when moths are present. Spray your mix of neem oil and water all over your fruit trees, taking special care to spray all the fruit.
Works best when sprayed on developing fruit.http://www.kings.co.nz/bags/roll-products/bug-net-per-m
When diluting neem oil, using warm water makes it easier to mix up your spray.
Other Sprays
Currently no insecticides are registered for use on Guava Moth. However sprays that work on Codling Moth, such as Success Ultra are likely to be effective. For best results, use in conjunction with a pheromone trap to help you time your spray.
Note: Success Ultra should only be sprayed 4 times a year otherwise insects are likely to build up a resistance.
Removing Fruit
Infected fruit should be removed and disposed of carefully. Don’t add infected fruit to your compost.
Covering your Fruit
Cover the fruit or the entire tree with Bug net as the fruit first starts to develop. Fruit only becomes infested with the larvae if the moths can lay their eggs on the fruit. Don’t cover the tree during flowering as the flowers won’t get pollinated by bees and other pollinator insects.
Biological Control
While really effective biological controls are yet to have been discovered, planting to encourage beneficial predator insects into the garden/orchard is likely to help.
Plants to attract beneficial predators insects includes: borage, alyssum, hyssop, sage, lavender, and echinacea (coneflowers). For more ideas on attracting beneficial predator insects click here