Ruud Kleinpaste: Codling moths and a trick to thwart them

Codling moths are a pain in the backside for people that grow apples. A week or so after flowering, the fertilised, tiny apples (known in the UK as “codlings”) are the perfect target for the moths to lay eggs in.  The caterpillars emerge from the eggs and tunnel into the developing fruit, causing ugly tunnels, often with fungal infection, brown decay, and “frass” sticking out of the hole. Once these caterpillars are inside, you won’t get them out and the fruit will be rather awful as it develops.  In the old days we used to regularly spray pretty nasty insecticides on our apples: Carbaryl, Organophosphates, etc. Not nice!  The moths are quite pretty: golden colours, about a centimetre in size, flying around the orchard when the flowering has just finished.  The caterpillars exit the fruit when full grown – they descend down the stem/trunk and pupate in loose bark or further down in the soil.  A second Generation develops in summer, especially in the northern parts of NZ.  Second generation moths can be detected by using a Codling Moth pheromone trap, which indicates exactly when the moths are flying again, looking for mid-summer sized apples to lay their eggs on.  Those sticky pheromone traps will trap some of the moths, but not in sufficient quantities to significantly reduce their numbers in your home “orchard”.  To really get rid of the majority of codling moths you better use a specific virus that knocks the caterpillars out before they take their second bite of the apple. This virus only targets codling moths and no other insects. That Virus is called MADEX 3, and the active viral particles are a Granulosis Virus. Excellent and safe to use, unless you look like a codling moth caterpillar!  A couple of stockists of Madex 3 who focus on the DIY online business are: Good to Grow and NZ YUZU. Commercial distributers who purchase somewhere nationally but may not stock Madex at every branch are: Farmlands, PGG Wrightson, Fruit fed Supplies, Horti centre, etc.  This is a commercial product, used by apple growers – it covers large orchards and is very effective indeed. It is also quite pricey (around $180 for 100 ml) but if you put it in the freezer and only use what you need, it’ll last for many, many years. Share it with your neighbours to cut costs, follow the instructions, but KEEP IT IN THE FREEZER AFTER USE.  It’ll be time to use it in the next week or so!  LISTEN ABOVE See omnystudio.com/listener for privacy information.