Organic pest control is coming into its own as researchers find better ways to control insects and other unwanted garden guests while causing minimum harm to the environment.
Gardeners are using microbes, natural insecticides made from plant extracts, and even minerals to get rid of unwanted insects. Once looked at askance, these methods are finally coming into their own as viable controls.
Microbes
Bacillus thuringiensis (Bt). A bacterial disease that infects insects, it was first discovered and recognized in 1911. Even then, it took another 40 years for Bt to become available commercially. This bacillus is the active ingredient in some insecticides. It’s considered safe for humans, pets and wildlife. Bt works in the gut of insects, paralyzing the digestive process. Infected insects stop feeding within hours after ingesting the bacillus. They usually die from starvation in several days. Various strains of Bt have been developed to control different insects. One strain kills only certain caterpillars. Others control mosquito larvae, black flies and some types of gnats. Bt can be found in Dipel, thuricide, Mosquito Dunks, among other products. However, Bt strains that kill mosquito larvae are not effective against caterpillars and vice versa.
Bacillus subtilis.This bacteria prevents fungal disease. It also controls existing plant disease. There are many uses of Bacillus subtilis. It is used to control fungal disease on grapes; early blight in tomatoes; powdery mildew, affecting cucumbers; and fireblight, which attacks pears.
Gliocladium virens. This bacteria is a fungus itself. Like Bt and other beneficial microbes, it occurs naturally in soil. It controls damping-off disease, pythium rot and fusarium.
Saccharopolyspora spinosa This is an actinomycete found in the soil. It resembles fungi. It is used to control caterpillars, thrips, fire ants, bagworm, tent caterpillars. It is sold as Spinosad and others. It controls a wide range of insects.
Contact insecticides
Insecticidal soaps. These are natural, organic soap products that are not harmful to plants or to beneficial insects, but work well on a variety of insect pests. Itkills aphids, earwigs, grasshoppers, harlequin bug, leafhoppers, mealybugs, mites, plant bugs, psyllids, sawfly larvae, soft scales, spider mites, squash bug, blossom thirps and whiteflies. There are directions on the Internet on how to make homemade insecticidal soap
Horticultural oils. These are not petroleum-based oils, although there are some petroleum-based products on the market sold as horticultural or dormant oil. Read labels carefully and make sure that the product is organic. Horticultural oils kill small, soft-bodied pests such as aphids, mites, caterpillars, mealybugs and scale insects. It is commercially sold as Neem Oil, GreenLight Dormant Oil, Rose Defense.
