With more and more people turning to organic gardening, the sale of artificial insecticides has witnessed a slight decline. Organic gardening emphasizes on natural methods, right from use of fertilizers to pesticides. Synthetic fertilizers and pesticides can be harmful to the ecosystem. Apart from causing harm to the beneficial organisms in the soil, such chemicals may also seep into the ground water. They may also affect pets and even humans. So natural or botanical insecticides are always preferred to synthetic ones. These insecticides are made of natural substances, and are found to be safe for animals, humans as well as the environment.
Natural or botanical insecticides can be homemade or store-bought ones. Neem oil is one such insecticide that has been used through the centuries. Even garlic and nicotine can be used to control pests. You may also go for insecticides like sabadilla, pyrethrin, and rotenone. Botanical insecticides can be of different types. All you have to do is to use the right one for a specific pest, that too in the right manner. You must have a basic idea about such insecticides, and the method of using them.
Neem oil is extracted from the seeds of neem trees. This oil with a pungent smell, has been used as an insecticide, for a very long time. While it can be toxic to some insects, others get repelled due to the smell of this oil. It is said that neem oil affects the hormonal balance of certain insects, thereby causing their death, before their next molting stage. Apart from controlling insects like white fly, aphids, and Japanese beetles, neem oil is also an excellent miticide as well as a fungicide. It is not toxic for beneficial insects, humans, and animals. Neem oil has to be diluted with water before it is applied on plants.
Pure nicotine is toxic to animals as well as humans, hence it is best used in diluted form. Most of the store-bought nicotine insecticides are found to be 40% liquid concentrates, that have to be diluted with an ample amount of water before application. It is useful in controlling white flies, aphids, thrips, leaf hoppers, etc., and is usually applied during warm weather, for maximum effect. You may also prepare a homemade natural insecticide with nicotine, by boiling around 100 cigarettes in four liters of water. Keep the water overnight, and strain it before storing. You have to mix one part of this mixture with two parts of water, before spraying it on plants.
Sabadilla is produced from the seeds of a plant, that resemble lilies in looks. The active ingredient in sabadilla is an alkaloid called veratrine. It is highly toxic to insects which come into contact with this insecticide or ingest it. This insecticide is mainly used in the form of dust or spray, and is found to be non-toxic to humans as well as animals. However, make sure to wear masks while using this insecticide, as inhalation may cause sneezing. It can also cause irritation of the eyes.
Pyrethrin and Rotenone
Obtained from Dalmatian chrysanthemum, pyrethrin is a botanical insecticide that attacks the central nervous system of insects. It is available in the form of dust as well as liquid suspension. It has been observed that in small amounts, this insecticide may not be toxic to insects, but still may repel them. However, in large amounts, it can be slightly toxic to humans as well as animals. As far as fish is concerned, pyrethrin can be toxic. Rotenone is another insecticide that is derived from the roots of plants that belong to the genus Derris. It is mainly used as a dust or spray, and it can be slightly toxic to mammals. As with the case of pyrethrin, rotenone is also toxic to fish.
Natural insecticides can be prepared at home, using materials that are easily available in the kitchen. They include garlic, cornmeal, and cayenne pepper. Crushed garlic boiled with water is found to be effective in controlling soft-bodied insects, like aphids. Cornmeal sprinkled around plants can prove deadly for horn worms. They cannot digest cornmeal. Even tea prepared with petunia leaves may prove useful for repelling horn worms. Using sulfur dust is good for controlling thrips, that can also be repelled with garlic and onion sprays. Application of garlic and chili pepper sprays will reduce mites in your plants. Even soap sprays are found to be useful in controlling several pests.
You may find various other botanical insecticides, like citrus oil and ryania. Apart from that, you may also resort to beneficial nematodes, which are roundworms that can cause damage to the internal organs of the pest, which are mainly insects and insect larvae. You must consult an expert horticulturist and gain thorough knowledge about these insecticides before using them. You must also know which one is ideal for your crop, when to apply it, and how much is needed.