Killing worms in trees can be tricky. Why? The many different types of chemicals and pesticides used to kill pests can actually end up killing the beneficial earthworms living in the soil below. Without earthworms, your precious pecan tree, milkwood tree or apple tree could not survive. Earthworms play an important role in helping the earth’s trees, plants, fruits, and vegetables thrive. Earthworms do several things for the earth. They aerate the soil, which means they dig tunnels in the soil, allowing air to get to the plant roots and worms eat organic matter, digest it, and excrete the digested material. The digested material, called “castings” are rich with calcium, phosphorus, and potassium – the building blocks of a healthy landscape.

Worm castings are so valuable and ten times richer in nutrients that commercial topsoil, that many gardeners and farmers use the composting method to fertilize plants and crops. Worm castings also help create channels within the layers of the earth’s soil, which helps to hold water better and keep moisture in the soil longer.

To avoid killing earthworms, it is important to make sure the pest that has infested your milkwood, pecan, or apple tree does not have any of the characteristics of an earthworm. Just a few of the characteristics used to identify earthworms include Genital tumescene (GT), the Tubercula pubertatis (TP), and the Clitellum. The clitellum of adult earthworms contains features called genital tumescence, and tubercula pubertatis. The clitellum features, the male pores, and female pores are found above the clitellum and are all parts of the earthworm reproductive system.

Earthworms also have “setae” which are tiny hair-like projections that are arranged in rows along the earthworm body. The setae are used are used for locomotion by the earthworm. The prostomium is the earthworm mouth. The size, shape, and position of the different characteristics of the worm are different in different species of earthworms and will help you to identify the species of earthworms you may be dealing with.

Once you have made the determination that the pests are not earthworms, you can begin treatment. Try using Dipel Dust & Spray or Bacillus Thuringiensis (Bt). Fortunately, these insecticides are harmless to people and they are not considered toxic to friendly insects. If you decide to use anything stronger than these biological insecticides, please consider hiring a professional home and garden exterminator. A professional home and garden exterminator will know exactly how to kill the pests in your trees without killing earthworms or causing any further damage to your trees.

For more information on how to control pests in your garden and trees, visit the University of California Agriculture and Natural Resources website at http://www.ipm.ucdavis.edu/PMG/r107303211.html.

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