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  • What’s the best way to prevent wormy apples?

    Created by Shaylynn on

    Hello –

    I am a new apple orchard owner. Last year our apples had every kind of pest imaginable, codling moths being one of the big ones. I do not want to need to wash my fruit before I eat it, so I am looking at preventative control options for wormy apples. My question is when purchasing the trichogramma wasps, what is the shelf life before they hatch? Can it be controlled? Do I need to buy new squares every time I plan to release them? Ideally, I would love to but a card, and set out one every week as needed. How does this work? I am getting the idea that I need to hang the traps for the moths, then release the moths according to how busy the traps are? Please elaborate!


  • Author
  • #266148

    Eric Vinje

    Hi Shaylynn –

    Use pheromone traps to determine when codling moths arrive, then release trichogramma wasps to attack their eggs. Releases should be made when codling moths are first present and periodically thereafter. We suggest releasing 5,000 (1 square) per 5,000 square feet weekly, for 3-6 weeks.

    Note: Trichogramma wasps are shipped as pupae in host eggs, glued to paper strips, and arrive ready to hatch out as adult wasps. They can be stored after receipt for 2-5 days, between 47 – 50 F. However, the longer they are stored, the higher the mortality rate will be. DO NOT FREEZE.

    We also recommend the following organic treatments to prevent wormy apples. These products can be used by themselves or together (with trichogramma) as part of an integrated approach to codling moth control.

    Scrape loose bark in early spring to remove overwintering cocoons and then spray All Seasons® horticultural oil to eradicate eggs and first generation early instar stages.

    Beneficial nematodes are microscopic, worm-like parasites that actively hunt, penetrate and destroy immature stages of this pest. Spray on trunks and main branches, and also over the soil out to the drip line for a 60% to 90% mortality in pre-pupae.

    Surround WP — a wettable kaolin clay — can be used to deter a broad range of fruit tree pests (and diseases), and will reduce codling moth damage by 50-60%. Apply before moths arrive and continue for 6-8 weekly applications, or until the infestation is over.

    In areas of severe infestation, spray botanical insecticides when 75% of petals have fallen, followed by three sprays at 1-2 week intervals. These natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.

    Hope it helps!

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