Rudd Kleinpaste: Guava Moths on Feijoas

<p>A major problem up north is the Guava moth (<em>Coscinoptycha improbana</em>), found in Northland, Auckland, Waikato, and Coromandel.</p> <p>Hosts of this caterpillar are Guava, Feijoa, loquats, peaches, citrus, quinces, macadamia, apples, and pears; quite non-selective in its preferences.</p> <p>In Northland (wild) loquats are the fruit that hosts the caterpillars in late winter/spring, allowing the population to build up.</p> <p>People are now harvesting feijoas that have tiny entrance/exit holes in the fruit, allowing fungi inside the fruit, brown flesh, and rot. You’ll also find the caterpillar’s tunnels inside.</p> <p>Those caterpillars entered the feijoas when the fruit were still small but just starting to swell – well after flowering. This is interesting information when it comes to trying to control the little buggers spoiling your crop.</p> <p>Currently there are no insecticides registered for the control of Guava moth; some people use “Success”, a rather good caterpillar killer (Yates) and “on the Organic side” of pesticides as a by-product of bacterial <em>excrement</em>.</p> <p>Other folk use Neem Oil – regularly sprayed (every 7 days) on the developing fruit.</p> <p><strong>Both these control chemicals have limited effect</strong> – about 50%.</p> <p>There are no biological control organisms in NZ (Predators, Parasitic wasps, natural Guava moth diseases, etc).</p> <p><strong>Pheromone traps</strong> (that trap the lusty males) <strong>do not reduce the infestation</strong> – they just alert us to the timing of the flight season.</p> <p>“<strong>Attractants</strong>” such as vegemite etc., <strong>don’t work.</strong></p> <p><strong>Light traps are useless</strong> in controlling guava moths – most moths (more than 90%!!) caught are native moths of no relevance to feijoas.</p> <p><strong>What we do know</strong> is that later-maturing varieties/fruit are usually less affected by this caterpillar, and <strong>fine netting</strong> draped over the tree <strong><em>after</em></strong> <st