Do Peppers Kill Parasites?

The Main Ingredient -- Capsaicin

• The heat-inducing chemical in hot peppers, also known as chiles, is capsaicin. Although capsaicin produces what some people consider a pleasurable pain in cooking, it disrupts insects' nervous system and damages their cells. Capsaicin is the main ingredient in several commercial formulations and homemade sprays. Generally, these sprays are used to repel and kill plant pests, such as aphids, spider mites, thripes and whiteflies, both in gardens and on houseplants. Capsaicin, however, is also toxic to honeybees and should be used with caution when bees are pollinating trees, vegetables and ornamental plants.

Warnings and Safety Precautions

• Before working with hot peppers and pepper formulations, put on disposable gloves, safety goggles, long pants and a long-sleeved shirt, and work in a well-ventilated area. Capsaicin may affect your skin, eyes, mucous membranes and lungs if the volatile pepper juices splatter on you while you're making a homemade spray or applying a homemade or commercial spray. Washing your hands thoroughly with soap and water after handling any capsaicin product is essential. Also, put the gloves you used in a plastic bag before putting them in the trash, and wash your clothing with hot water and laundry detergent to remove the capsaicin from them.

Commercial Formulations

• A variety of commercial capsaicin products are available for use as insecticides and miticides on plants and to discourage rabbits, cats, dogs and other warm-blooded pests from eating or disturbing gardens. When applying a ready-to-use insecticide product on a plant, test it on one or two of that plant's leaves first. If those leaves don't appear damaged after one or two days, then spray the product on the plant until its leaves, flowers and fruits are wet but not dripping wet. The spray should be allowed to dry completely before you touch the plant with your bare hands. Avoid spraying if rain is forecast within 24 hours.

Homemade Bug-Killing Spray

• Mixing your own bug-killing spray is relatively simple. The project begins with placing 1 cup of hot peppers, such as jalapenos or habaneros, and 2 cups of water in a blender and blending the ingredients into a puree. Strain the puree through cheesecloth in a strainer and into a bowl, and then pour the bowl's liquid into a spray bottle. Testing the homemade pepper spray on the plant you intend to treat for parasites is important. Spray one leaf of the plant, and wait 24 to 48 hours to ensure that it doesn't damage the plant before soaking the plant's leaves and pests with the homemade spray. For an additional bug-killing effect, add 1/2 teaspoon of dish-washing liquid soap or castile soap to the mixture.