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There are natural ways to fight pests

| Friday, May 3, 2013, 8:57 p.m.
Jessica Walliser
When planting fruit trees, like apples, make sure to look for tree fruits that are bred to have an innate resistance to pests and diseases.

There are several common insect pests that like to frequent home orchards here in the East, and it's important for gardeners to follow a few important steps to keep them at bay. Since spraying chemical pesticides is no longer a part of my gardening repertoire (and hasn't been for the past 15 years), I'd like to introduce you to some of the ways you can grow beautiful fruit without resorting to chemicals.

First and foremost: If you are new to growing tree fruits and you haven't yet purchased trees, know that variety selection matters greatly. Look for apples, peaches, plums, pears and other tree fruits that are bred to have an innate resistance to pests and diseases. Don't just buy whatever tree you can find. Do your research, and purchase only resistant varieties.

Here are four of the most common insect pests found on fruit trees here in the East, along with some ideas on how to manage them naturally.

Apple maggots: Female flies lay eggs just under the skin of the apple. As the larvae (maggots) hatch, they tunnel through the fruit. Though they are most common on apples, you also may find them on plums, pears and cherries. The best preventative method for small, home orchards is to hang red sphere traps, coated with a non-drying glue, on the trees in mid-June. Hang a single sphere on dwarf trees and up to six spheres on full-sized trees. The red balls lure and trap the adult flies, who think they are ripe apples and land to lay their eggs.

Coddling moths: These moths attack apple, pear, peach and quince. Eggs are laid on developing fruit or leaves, and in a few weeks, the newly hatched larvae create tunnels inside the fruit. They often are found near the core feeding on the seeds. They then leave the fruit through a separate exit hole and start the cycle again, often producing two generations in a season. The best preventative method for home gardeners is to use pheromone traps to lure and capture the adults. These traps are hung in the trees a few weeks before bud break and need to be replaced in July to control the second hatch. Two traps per full-sized tree will suffice.

Plum curculio: Spring is prime time for the plum curculio. This black-brown, snout-nosed insect plagues its namesake, but will also attack nectarines, peaches, cherries, apricots and pears. Starting at bloom time, females lay eggs under the skin of the immature fruit and create crescent-shaped scars. A week later, the newly hatched larvae bore through the fruit to feed. To prevent damage from plum curculio, turn to safe, yet very effective, kaolin clay products. Sprayed on the fruit as a liquid, it dries to form a thin, powdery barrier around the fruit, repelling the adults and preventing them from laying their eggs. Begin spraying at petal drop and continue to do so every seven to 10 days for about eight applications. Trees look a little funny coated in the white spray, but it's well worth it. Kaolin clay products also work great to help deter apple maggots and codling moths.

Peach tree borers: The larvae of a moth, peach tree borers attack peaches, plums, cherries, nectarines and apricots. Adult moths lay eggs on the bark in mid to late summer, and the larvae burrow under the bark, tunneling between the inner bark and the sap wood. They overwinter in the tree, then emerge as adults early the following summer. Pheromone traps are useful to capture and monitor the adults. But the best method for controlling the borer is to carefully examine the tree trunk for small holes and bits of sawdust every fall. If you find an entrance hole, push a piece of straightened wire in, as far as it will go, to squash the borer. A species of beneficial nematodes can also be injected into the hole using a needleless syringe. The USDA's Agricultural Research Service found that applications of this nematode, Steinernema carpocapsae, were able to control peach tree borers as well as chemical applications in small field trials.

To purchase any of the pest-control products and/or traps I mention above, ask your local nursery. If they can't get them, online and catalog sources include Peaceful Valley Farm Supply (, Planet Natural ( and Arbico Organics (

Send your gardening or landscaping questions to or The Good Earth, 503 Martindale St., 3rd Floor, D.L. Clark Building, Pittsburgh, PA 15212.

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