As its name implies, an insecticide kills insects by means of chemical exposure. It destroys all forms of an insect species, from the eggs and larvae to the adults. Therefore, an insecticide differs from a repellent, which only keeps the insects away from a designated area. Insecticides come in many forms and fit within an integrated pest management strategy with pesticides, herbicides and fungicides.
Insecticide Use and Abuse Most insecticides come in spray form, such as aerosol cans and crop dusters. Insecticides have the potential to eradicate many beneficial insect species and alter an ecosystem, so it takes careful planning and application when using any type of insecticide. Insecticides contain toxic chemicals that harm people and animals; however, the labels include instructions and precautions for safe use. In addition, wash any fruits or vegetables that grow in areas of application.
Types of Insecticides
All insecticides fit into a specific category based on their method of application and how they enter an insect's body.
Stomach insecticides – Apply this insecticide on plants, wood and other surfaces. Insects consume it and die as a result.
Contact insecticides – Spray or dust this insecticide on soft-bodied insects. It penetrates their body wall and kills them on contact.
Systemic insecticides – This type of insecticide penetrates plant tissues and kills the insects as they feed on the sap.
Fumigants – Use fumigants for insects that lurk within walls and other out-of-reach places.
Residuals – Apply residual insecticides to plant leaves, livestock, pets and surfaces where insects congregate. The insects absorb the poison and die as they touch the target area.
From fumigants to residuals, insecticides eliminate certain insects and offer curative maintenance for infestations. Apply all insecticides according to the instructions on the label, and always wear protective gear to avoid contamination. Depending on the type of insecticide, it can take anywhere between hours and seconds for it to take effect.