The use of chemical agents to kill and control pests transformed modern agriculture. Many pesticides are common amongst gardeners as well. Chemical pesticides include three different classes of chemicals: herbicides, insecticides and fungicides. Each controls a specific type of pest and each has its own advantages and disadvantages. Weigh your options before using any chemical pest control to find one appropriate for your needs.
Efficiency
Pesticides offer a fast-acting and often highly effective means to kill or control a specific type of pest. Sometimes chemical pest control may be the only currently available option against a particular pest or insect. As noted in "Sustaining the Earth", according to the Food and Agriculture Organization some 55 percent of the world's potential food supply is lost to pests. Proponents of chemical pest control contend that without pesticides, losses would be far worse. There are a wide variety of chemical pest control products on sale at many home and garden stores; by choosing the right product, you may be able to minimize the damage a particular type of problem pest inflicts on your plants and grow a healthier, more attractive garden.
Evolution
Overuse of chemical pest control promotes the evolution of pesticide resistance. When pesticides are applied, the individuals that are most resistant are most likely to survive. If their resistance to the chemical has a genetic basis, they will in turn pass these genes on to their progeny so that the population becomes more resistant over time. In other words, chemical pest control acts as a type of artificial selection for pesticide resistance. According to "Essential Environment," by 2000 there were over 2,700 known cases of resistance by 540 species of pests to over 300 pesticides, including the diamondback moth and the green peach aphid, both of which are agricultural pests.
Toxicity and Non-Target Effects
Many pesticides can not only kill beneficial organisms but pests as well. Pollinators like bees or natural predators like ladybirds may be susceptible to pesticides; pesticides may also be toxic to wildlife or to pets. If mishandled or misused, some pesticides can also be toxic to humans. Using pesticides can potentially destroy beneficial organisms or wildlife and thereby harm both your garden and the environment.