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Tuesday, January 12, 2016

Wormy Apples Pest Problems Vary with Regions

Q. I have a Fuji semi-dwarf apple tree that is about 23 yrs old in Kingman, AZ. The last few years I’ve had a terrible problem with worms in the apples. I clean up all the leaves after they fall and remove any apples that don’t fall. I  I spray dormant oil right before the flowers buds emerge or sooner and spray all around the area including on the grape vines nearby. I have wood chip mulch about an 8 foot diameter around the trunk. I’ve even sprayed Neem oil once when the apples are about the size of marbles but to no avail. Now I’m wondering whether I should remove the wood chip mulch as this seems to be the only thing left to try other than continual spraying or trying stronger chemical type sprays which I’d rather not do. What do you recommend?

A. Most likely this is codling moth and they attack the fruit several times during the year. Codling moth is an international pest of apples and pears. Their emergence coincides with rising temperatures and if you do not get control of the first flight they can multiply rapidly and each new generation can bet worse. 
Codling moth on immature pear fruit in Afghanistan
Codling moth damage on apple in North Las Vegas, NV
I am getting ready to begin writing up how to use pheromone traps for eliminating codling moth, rather than pesticides, in backyard and small scale operations if codling moth is not a huge problem in the area. I may also offer some classes on how to use them. I have been trapping insect pests like these with sticky cards and traps for years. They can be a very powerful tool for insect management.

If codling moth is a huge problem in your area, this might not work for you but it is worth a try. Stay posted and follow me on my blog for more information.

1 comment:

  1. Footies w/ WP: (physical protection-100% effective, organic, labor intensive)





    Since codling moth larvae continue to develop in fruit that has dropped from the tree, it’s important to remove windfall fruit throughout the season.

    Mature larvae emerging from fruit search for places to build a cocoon on tree bark. Corrugated cardboard strips 2-3" wide, secured snugly around the tree trunk, provide secluded places for larvae to spin their cocoon and pupate. However, corrugations must be large enough for larvae to enter. The strips must be checked often from [This is for Utah, Kingman may start earlier] June to September (every 10-14 days), destroyed and replaced to effectively eliminate insect larvae.

    Individual developing fruits may also be covered with paper bags (or muslin cloth or organza bags). Bags should be secured well, but must not constrict the twig. Remove the bags a short time before the fruit is mature to allow the fruit to color.


    Codling Moth also attacks pears, quince, walnuts, and other tree fruits: (hawthorn, apricot, plum, peach, cherry)

    Pupae - Found in a silken cocoon located in bark
    crevices, orchard debris, in fallen fruit, or other
    protected place.

    Upon hatching (8 to 15 days later), the
    larvae enter the fruit (usually by way of the calyx
    cup at the blossom end, but they can enter
    anywhere) and tunnel directly to the center of the
    fruit. They devour portions of the fruit and seeds
    and then tunnel their way back out, leaving behind
    masses of brown excrement; they feed in the fruit
    for 21 to 30 days.

    Organic controls that were tried include Cyd-x (coddling moth virus) and apple bags.

    The apple bags had a 98 percent success rate after two cover sprays were applied before putting bags on the apples. The down-side to apple bags is the time spent placing a bag around each apple, then removing it later in the year.

    Kaolin clay (Surround WP), when maintained as a complete barrier on fruit surfaces, can reduce codling moth infestations.