A pesticide is a substance used to kill pests. Depending on their target, pesticides can be categorized as insecticides (for killing insects), herbicides (for killing weeds), fungicides (for killing fungi), and so on.
Pesticides can be labeled as organic or synthetic.
- Organic and natural pesticides are naturally occurring substances like plant oils or mineral formulations that are noxious to pests.
- Synthetic pesticides are manmade compounds, though many are inspired by natural, toxic substances. However, synthetic pesticides are generally modified to be more potent or environmentally persistent.
Since all pesticides are ultimately designed to be lethal, a chemical's designation as synthetic or organic does not necessarily mean that it is more or less toxic.
Effects on non-target species
Beneficial, non-target organisms like pollinators are exposed to pesticides, including insecticides, herbicides and fungicides, while foraging from flowers or nesting in the soil. Though herbicides and fungicides are not applied for insect control, these chemicals can still disrupt vital molecular processes in insects.
Pesticides contain many chemicals: active ingredients and additives.
- Active ingredients are toxic and non-discriminatorily kill living things.
- Additives help pesticides evenly adhere to surfaces or penetrate insect cuticles.
Additives are assumed to be “inert" and are not environmentally regulated like active ingredients. However, research shows that some additives alone can harm pollinators. Pesticides are generally designed to persist on target plants, but pesticides can contaminate neighboring habitats through aerial drift, underground leaching and runoff.