Managing the guava moth
Newly introduced garden pests are the bane of the home gardener. The guava moth first appeared in Northland in 1997, but MAF did not get involved till 1999.
By 2002 Northland orchards were found to have some degree of infestation, and since then commercial growers and home gardeners in other parts of the North Island and possibly some areas of the South Island could have small, but growing populations of the pest.
When MFAT looked at Australia where the moth came from, it was reported as not being a problem in commercial orchards, only as a home garden pest. The same was also said of the potato/ tomato psyllid, which has since become a major problem here for commercial and home growers. Because the guava moth has numerous host plants including citrus, loquat, plums, peaches, pears, apples, macadamia, feijoa and guava they are likely to find fruit to infest at any time of the year. There is a lack of real infor- mation about the moth. It would appear that after laying eggs, possibly directly on the target fruit or nut crop, the caterpillars hatch out in 10 - 15 days, and then eat their way into the fruit.
A spray of Wallys Super Neem Tree Oil mixed with Raingard (effective against codlin moth) should stop the caterpillars from feeding. A repeat spray over the fruit (no need to spray the whole tree) every 14 days till harvest should begin eliminating the moths. Another fix is to wrap a branch in crop cover after flowering is finished to stop moths laying eggs on its fruit.
Set up inexpensive solar lights to attract the moths at night. Cover the lights with plastic wrap coated in cooking oil or petroleum jelly. The moths are attracted to the light and get stuck on the coating. Dispose of them next day and reload the trap. Wallys Yellow Sticky White-Fly traps could also be used in conjunction with solar lights to hang on a pole at about the height of the lowest fruiting branch of the tree.
Remember that lights on your property at night (including nearby street lights) act to attract moths and other nocturnal pests.
Online research indicates that as most host fruit trees have a period of a few months from pollination to harvest, it is likely that two or more generations of moth will affect the same fruit tree. The grubs pupate over 14 days, in the top layer of soil and debris under the trees they have been feeding on. A gang of free ranging chickens would clean up any pupating moths no problem. No chickens? Try Neem Tree granules. Sprinkled under the trees these work to confuse codlin moths when they emerge from their cocoons, and may do the same for guava moths if indeed they find their host plants by smell. Other ideas propose planting aromatic herbs or plants under the trees to confuse the moths, or using a regular olive oil and garlic spray programme.
Problems ring me at 0800 466 464 (Palmerston North 357 0606) Email firstname.lastname@example.org
Web site gardenews.co.nz
Bug expert Peter Peckham, shows the distinctive markings of a guava moth, another imported garden pest.